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Final Report for Priority Green Clarington – Water and Energy Demonstration Project (February 16, 2016)

Disclaimer:

The Priority Green Clarington – Water and Energy Demonstration Project report is intended provide general information and to encourage discussion. The information and results presented in this report are based on the data collected from the six “better than code” demonstration homes (relative to the 2012 Ontario Building Code) over a one year monitoring period. Water and energy savings, greenhouse gas reductions, and the financial evaluation are estimates based on the data collected and are relative to the minimum requirements of the 2012 Ontario Building Code. Different factors, including construction methods, equipment installed, and household demographics and behaviour, may yield different results.

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c o l o g i c a l

e s i g n r e e n

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Final Report

For

Priority Green Clarington -

Water and Energy

Demonstration Project

February 16, 2016

Final Report Priority Green Clarington Water and Energy Demonstration Project

February 16, 2016

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Accessibility Statement:

If this information is required in an alternate format, please contact:

Amy Burke, Priority Green Clarington Coordinator

Planning Services Department

905-623-3379.


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Acknowledgements

Priority Green Clarington has received funding support from the Government of Ontario

through the Showcasing Water Innovation Program, Ontario’s Independent Electricity

System Operator (IESO), and from the Green Municipal Fund, a Fund financed by the

Government of Canada and administered by the Federation of Canadian Municipalities.

Such support does not indicate endorsement by the Government of Ontario, IESO, the

Federation of Canadian Municipalities, or the Government of Canada of the contents of

this material.

The Municipality of Clarington is grateful for this funding support, as well as the support

and input that has been received from many throughout this project, including the six

participating families.

Demonstration Project Partners:

Region of Durham

Brookfield Residential

Halminen Homes

Jeffery Homes

Staff Working Group Members:

Municipality of Clarington

Leslie Benson, Manager, Development Engineering & Traffic, Engineering Services

Amy Burke, Priority Green Clarington Coordinator, Planning Services

David Crome, Director, Planning Services

Carlo Pellarin, Manager, Development Review, Planning Services

Rick Pigeon, Chief Building Official, Engineering Services

Carlos Salazar, Manager, Community Planning & Design, Planning Services

Cindy Strike, Principal Planner, Planning Services

Region of Durham

Mike Hubble, Development Approvals, Works Department

Glen Pleasance, Water Efficiency, Works Department


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Technical Advisory Committee Members:

Central Lake Ontario Conservation Authority

Ganaraska Region Conservation Authority

Building Industry & Land Development Association (Durham Chapter)

Durham Region Home Builders Association

Veridian Connections

Enbridge

University of Ontario Institute of Technology

Durham College

Seneca College

The Municipality of Clarington and our partner builders wish to acknowledge the

valuable support by the following trades, product suppliers/manufacturers, and industry

organizations:

Brimar Contracting Ltd.

Gerald D. Brown Plumbing and Gasfitting Service

JAK Electrical

J&S Electric

New Way Plumbing & Heating

Nova Plumbing

BP Canada

Canplas / Recover® Greywater Systems

Ecobee

Maple Contracting

Martino Contractors Ltd.

Panasonic

Power Pipe Drain Water Heat Recovery Systems

Silver Carpentry

Velcan Forest Products

Water Matrix

Sustainable Housing Foundation


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Table of Contents

1.0 Executive Summary ............................................................................................ 1

2.0 Introduction ......................................................................................................... 5

2.1 Priority Green Clarington ........................................................................................................ 5

2.2 Regulatory Framework ........................................................................................................... 6

2.3 Green Demonstration Project ................................................................................................. 7

2.4 Participant and Home Overview ............................................................................................. 8

3.0 Monitoring Program ............................................................................................ 9

3.1 Electricity Sub-metering ........................................................................................................ 10

3.2 Water Sub-metering .............................................................................................................. 10

3.1 Gas Metering ........................................................................................................................ 10

4.0 Annual Energy and Water Consumption Modelling ....................................... 11

4.1 As-Built House Descriptions ................................................................................................. 12

4.2 Code-Built House Descriptions ............................................................................................. 12

5.0 Actual and Annualized Results ........................................................................ 13

5.1 Monitored Results ................................................................................................................. 13

5.1.1 Total Monitored Electricity Consumption by Sub-meter ............................................... 13

5.1.2 Total Monitored Water Consumption by Sub-meter ..................................................... 13

5.1.3 Total Natural Gas Consumption.................................................................................... 14

5.2 Modelling Results ................................................................................................................. 15

6.0 Analysis .............................................................................................................. 17

6.1 Energy Use Intensity ............................................................................................................. 17

6.2 Water Use Intensity .............................................................................................................. 18

6.3 Greywater Recycling System Efficiency ............................................................................... 19

6.4 Greywater Recycling System Water Quality Testing ........................................................... 21

7.0 Financial Assessment ....................................................................................... 23

7.1 Methodology ......................................................................................................................... 23

7.1.1 Simple Payback ............................................................................................................ 23

7.1.2 Net Present Value ......................................................................................................... 23

7.2 Escalation Rates ................................................................................................................... 24

7.2.1 Electricity ....................................................................................................................... 24


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7.2.2 Natural Gas ................................................................................................................... 25

7.2.3 Water ............................................................................................................................. 25

7.3 Financial Assessment Results .............................................................................................. 25

8.0 Comparison of HERS Rating to EnerGuide Rating ......................................... 31

8.1 Home Energy Rating System Index ..................................................................................... 31

8.2 EnerGuide Rating System .................................................................................................... 32

8.3 HERS and EnerGuide in the GDP ........................................................................................ 33

9.0 Benchmarking of GDP Homes ......................................................................... 36

9.1 Provincial Energy Benchmarking .......................................................................................... 36

9.2 North American Water Consumption Benchmarking ........................................................... 36

9.3 Neighbourhood Water Consumption Benchmarking ............................................................ 38

10.0 Heating, Electricity, Water-Related Energy and GHG Emissions .................. 40

10.1 Greenhouse Gas Reduction from GDP Homes ................................................................... 40

10.1.1 Grid Delivered Electricity and Natural Gas ................................................................... 40

10.1.2 Water Consumption Related Greenhouse Gas Emissions .......................................... 43

10.1.3 GHG Reductions from House Energy and Water Reductions...................................... 44

11.0 Municipal-Level Water Consumption Reduction/Avoidance ......................... 46

11.1 15-Year Extrapolation of Reductions .................................................................................... 48

12.0 Overall Findings, Recommendations, and Lessons Learned ........................ 50

13.0 Bibliography ...................................................................................................... 54


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List of Tables

Table 1 - Results Summary Table ......................................................................................................... 2

Table 2 - Summary of Financial Analysis .............................................................................................. 3

Table 3 - Summary of Energy and GHG Reductions by Category ........................................................ 4

Table 4 – GDP Home Overview ............................................................................................................ 8

Table 5 – Sub-meters by GDP Homes .................................................................................................. 9

Table 6 – Monitored Electrical Consumption by End-Use ................................................................... 13

Table 7 – Monitored Water Consumption by End-Use (L) .................................................................. 14 Table 8 - Annual Natural Gas Consumption by Home ........................................................................ 14

Table 9 – Annual Modelled Energy Consumption ............................................................................... 16

Table 10 – Annual Modelled Water Consumption ............................................................................... 16

Table 11 – Energy Use Intensity .......................................................................................................... 18

Table 12 - Water Use Intensity ............................................................................................................ 19

Table 13 – Greywater Recycling System Efficiency ............................................................................ 20

Table 14 - Effects of Purge Frequency on Greywater System Efficiency ........................................... 21 Table 15 – Historical Annual Electricity Rate Escalation ..................................................................... 24

Table 16 - Financial Analysis Summary .............................................................................................. 29

Table 17 – EnerGuide: Typical Energy Efficiency Ratings .................................................................. 32

Table 18 – HERS Index Scores (Pre-Occupancy) .............................................................................. 33

Table 19 – EnerGuide Ratings (Post-Occupancy) .............................................................................. 34

Table 20 – Comparison of Rating System Savings Modelled HERS and HOT2000 Energy

Consumption ........................................................................................................................................ 34

Table 21 - Ontario Benchmarking ........................................................................................................ 36

Table 22 - Indoor Water Use Benchmarking ....................................................................................... 37

Table 23 - Neighbourhood Water Consumption Benchmarking .......................................................... 39

Table 24 - OBC 2012: CO2e Emissions Factors ................................................................................. 41

Table 25 - GDP Household GHG Emissions by Fuel Type ................................................................. 42

Table 26 - Municipal GHG Emissions Via Water Infrastructure .......................................................... 44

Table 27 – GHG Reductions from House Energy and Water Reductions .......................................... 45 Table 28 - 15 Year Extrapolation of Savings ....................................................................................... 49


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List of Appendices

Appendix A – Glossary of Terms

Appendix B – Data Source Matrix

Appendix C – Meter Specification Sheets

Appendix D – Analysis Methodology for Energy and Water Consumption Modelling

Appendix E – Green Practices Matrix

Appendix F – OBC 2012 Supplementary Standard SB-12 – GDP Compliance Package

Excerpt

Appendix G – HOT2000 Modelling Results

Appendix H – Greywater Recycling system Water Quality Testing

Appendix I – *This Appendix Intentionally Left Blank*

Appendix J – Financial Analysis of Energy and Water Conservation Features

Appendix K – Green Practices Validation and HERS Energy Rating

Appendix L – Water Consumption Related Greenhouse Gas Emissions

Appendix M – Sub-metered Monthly Data Bins – Energy, Raw Data

Appendix N – Sub-metered Monthly Data Bins – Water, Raw Data

Appendix O – Energy and Water Modelling – Annual Consumption Comparison


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1.0 Executive Summary

The Municipality of Clarington partnered with the Region of Durham and three local

builders for the Priority Green Clarington Green Demonstration Project. Six

demonstration homes, incorporating practices that aim to reduce their environmental

impact for water and energy beyond that of a home built to meet Ontario’s 2012 Building

Code, were constructed. Each of the demonstration homes were sold to interested

home buyers and monitored for a twelve month period.

This report represents an assessment of the Green Demonstration Project savings of

water and energy, utility costs and greenhouse gas emissions at the home and

municipal scales. Further it reports the cost-effectiveness of the measures that were

implemented and provides a high level demonstration of potential implications of

reduced water consumption on infrastructure development. Notably, the responsibility

for the provision of water and sewer services in Clarington falls to the Region.

A glossary of terms, acronyms, and water and energy efficiency measures discussed in

this report can be found in Appendix A.

A twelve month performance monitoring program under actual operating conditions was

completed. Performance monitoring included tracking of total water, electricity, and

natural gas usage, and water and electricity sub-metering of specific appliances and

water fixtures within the demonstration homes. Prior to the start of the monitoring period

the homes were tested for airtightness and a home energy rating performed using the

Home Energy Rating System Index.

The table below summarizes projected annual energy, water, and cost savings as

determined by modelling the project homes and comparing them to equivalent homes

designed to the minimum Ontario Building Code (2012) standards. Unless otherwise

noted, water use and savings referenced throughout this report refers to indoor

consumption.


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Table 1 - Results Summary Table

Home ID A B C D E F GDP

Average

Annual Energy Savings

kWhe 3,856 2,870 3,658 4,858 3,558 5,687 4,081

Annual Electricity Savings

kWh 97 16 1,653 742 324 2,119 825

Annual Natural gas Savings

m3 355 269 189 388 305 337 307

Average Monthly Energy Savings

kWhe/month

321 239 305 405 296 474 339

Average Energy Use Intensity Reduction

kWhe/m2/yr

20 21 25 19 18 20 21

Annual Water Savings

L 44,322 19,706 18,619 26,944 8,603 33,640 25,306

Savings in Litres per Capita per Day

LCD 40 18 26 18 6 23 22

Average Water Use Intensity Reduction

L/m2/yr 173 139 128 107 45 139 122

Annual Cost Savings $ $322 $182 $473 $400 $195 $745 $386

Electricity $ $19 $3 $331 $148 $65 $424 $165

Natural Gas $ $140 $107 $75 $154 $121 $133 $122

Water $ $162 $72 $68 $98 $31 $123 $92

Annual GHG Emissions Avoided from Energy & Water Savings

kg CO2e

775 558 1,051 1,095 706 1,542 955

The total annual cost savings on average were $386, ranging from $182 to $745 per

year. The actual performance of each GDP home was compared to an equivalent

model of the home designed based on the minimum requirements in the 2012 Ontario

Building Code. A range of comparative measures were examined, including energy use

and energy use intensity, water use and water use intensity, and greenhouse gas

emissions reductions. The GDP homes were found to be on average 11% more energy

efficient and 14% more water efficient than the equivalent code-compliant house.


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Further, in all cases the GDP homes demonstrated more favourable energy use and

water use intensity, and had a smaller greenhouse gas footprint than the equivalent

code-compliant house.

Three of the GDP homes were outfitted with a greywater recycling system that treated

and recycled shower water for toilet flushing. On average, the greywater recycling

systems saved 17,423 L of municipal drinking water annually – the range was from

13,510 L to 22,170 L and amounts to average annual savings of $64. The average

efficiency of the greywater recycling systems was 59%, but ranged from 42% to 77%. In

other terms, this reduction of water use amounts to, on average, 13 L per person per

day1 – a significant figure. The presence of a greywater recycling system within a home

had such significant impact on the home’s water savings that parts of the water analysis

in this report will be split into two categories – homes with greywater recycling systems

installed and homes without. The financial analysis found all water conservation

measures, except for greywater recycling, to be financially viable with positive net

present values.

A financial analysis, using both simple payback and net present value, was performed

on the green practices implemented in the green demonstration project, the results are

summarized here:

Table 2 - Summary of Financial Analysis

Green Practice Simple Payback Net Present Value

Years $ (2015)

Envelope and HVAC Energy Conservation Measured (Bundled)

13.5 $ 3,065.00

Domestic Hot Water Heater 6.3 $ 1,130.00

En-suite Shower Faucet 2.1 $ 740.00

Kitchen Faucet 4.2 $ 1,170.00

Greywater Recycling System 60 $ (1,740.00)

Ultra-Low Flow Toilets 2.1 $ 980.00

Whole Home 22.8 $ 2,270.00

A comparison of the HERS ratings with EnerGuide ratings was performed to showcase

two energy rating systems which are approved by the OBC; the HERS ratings were

further augmented in order to facilitate a comparison with more closely matching usage

assumptions. Under both the pre-occupancy and post-occupancy scenarios that were

1 Daily water savings of 13L per person equates to 10% of a person’s daily indoor residential water use

based on GDP consumption data collected.


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examined and irrespective of the rating system used, the difference in scoring reflects

the increased efficiency gained by the GDP homes through the implementations of

green practices that exceed the minimum OBC requirements. The scenarios serve to

demonstrate how energy modelling is better served by incorporating real world data as

available.

The impact of determined water savings in the GDP was quantified for Clarington’s

future forecasted development on centralized water supply and wastewater treatment

infrastructure, and provides a high level demonstration. In a scenario where no

greywater recycling systems are installed in the forecasted1,000 homes (on average)

constructed annually in the future, but all other water saving features are implemented,

the Region will avoid the pumping of 16.6 mega-liters of water and realize savings of

$35,300 annually2. In a scenario where these homes are outfitted with a greywater

recycling system alongside the other water saving features, the Region would

potentially avoid pumping 34 ML of water and realize savings of $72,3002 annually. The

savings figures in this forecast are first year savings only; the savings from homes built

in sequential years would compound on top of the annual savings realized due to the

previously constructed homes.

Further, analysing the energy and water related energy savings of a better than OBC

home yields energy savings and GHG emissions reductions over 15 years as shown

below; this summary is based energy and water related OBC improvements every 10

years as per forecast scenario B from Section 11 – Municipal Level Water Consumption

Reduction/Avoidance.

Table 3 - Summary of Energy and GHG Reductions by Category

Source Energy Savings GHG Reduction

MWh Tonnes CO2e

Energy 657,460 173,055

Water 1,274 463

Total 658,734 173,518

While the findings of the GDP are largely positive, and effectively demonstrate the proof

of concept with relation to water and energy saving features and design characteristics,

it is important to note that the six GDP homes do not represent a statistically significant

sample size.

2 Average savings figures in this section reflect first year realized savings based on 2015 utility costs and are expressed in 2015 CDN dollars with no expression of rate escalation.


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2.0 Introduction

2.1 Priority Green Clarington

Priority Green Clarington is an initiative of the Municipality of Clarington (Municipality). It

was established in 2012 as a response to forecasted population growth over the next

twenty years. Between 1991 and 2011, Clarington’s population grew by 70%, from

approximately 51,400 to 87,700 residents; by 2031, Clarington’s population is

forecasted to grow by another 60%. Focused on the principle of local planning for global

stewardship, Priority Green Clarington is intended to contribute to enhancing the

integration of sustainability into the residential land development process.

The vision of Priority Green Clarington is to set a new standard for residential

development that prioritizes sustainability, promotes innovation and continues to

improve the community’s quality of life. To achieve this vision, the Municipality, in

collaboration with the Region of Durham (Region), the private sector and the community

set out to:

Identify goals, targets and guidelines for green homes and neighbourhoods within

both new neighbourhoods and existing areas in Clarington;

Review current land development application and permit processes, policies, and

guidelines to identify new opportunities for supporting green homes and

neighbourhoods;

Collaborate with government and agencies involved in the development review

process, green design and building specialists, and the land development and

building community to define specific criteria for what qualifies as a “green

development application”;

Consider a variety of potential incentive mechanisms to encourage the voluntary

adoption of these criteria;

Contribute to the growing collection of knowledge about the opportunities and

challenges associated with green home practices through the execution of the

Green Demonstration Project (GDP).

The resulting green development framework is intended to send the message that

green development is a priority for building liveable neighbourhoods in Clarington. The

“Priority Green Clarington Green Development Framework and Implementation Plan”

(Municipality of Clarington, December 2015) was approved by Council on December 14,


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2015.3 Evaluation and learning through demonstration forms an important element of

the green development framework. This report presents the detailed results of the GDP

component of Priority Green Clarington.

2.2 Regulatory Framework

Starting in 2006, the Ontario Building Code (OBC) provided energy and water efficiency

requirements in tandem with the province’s policy of energy and water conservation.

These requirements aim to reduce the need for additional electrical generating capacity,

and to delay or eliminate expansion of municipal water and/or sewage infrastructure, all

of which have large capital costs. In this sense, the scope of the OBC has broadened to

include energy and water efficiency requirements.

For instance, newly constructed homes in 2007 would have been roughly 21% more

energy efficient than those built in the previous 1997 OBC standard. The stride in

residential energy efficiency was not as drastic in the 2012 OBC, with only modest

additional energy efficiency requirements being implemented and no changes applied to

the compliance packages. Look to the 2017 OBC for the next significant upgrades to

energy efficiency within ‘Part 9 of the Building Code: Housing and Small Buildings’.

On the water side, beginning in 2012, newly constructed or renovated homes are

required to be roughly 20% more water efficient than in the previous 2006 OBC. For

instance, the 2012 OBC requires high efficiency toilets (maximum 4.8 litres per flush

(LPF) as compared to a maximum 6.0 LPF introduced by the OBC effective October 1,

1996) be installed in new residential construction, as well as lower flow shower heads

(reduced from maximum 9.5 L/minute to 7.6 L/minute).

Effective January 1, 2017, the OBC will require all new low-rise homes under Part 9 of

the Building Code: Housing and Small Buildings to be constructed to be 15% more

energy efficient than those built in 2012. It is unknown at this time whether

strengthened residential water efficiency measures will also be required. Energy and

water efficiency requirements are expected to continue to increase as technology and

industry standards improve.

Another aspect of the evolving regulatory framework are provisions intended to promote

the use of particular green technologies. These technologies include, amongst others,

wastewater heat recovery and greywater reuse for flushing of toilets, urinals, or priming

of traps. As a result of changes made in the 2012 OBC, more opportunities for

3 Available at www.prioritygreenclarington.com

http://www.prioritygreenclarington.com/


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innovation are provided by expanding the end uses of rainwater and other non-potable

water.

2.3 Green Demonstration Project

The GDP aims to contribute in a meaningful way to the development of the 2017 OBC,

and to industry knowledge about the opportunities and challenges of green

development, and water and energy conservation. The GDP looks to reach beyond

policy and put green building into practice.

In collaboration with the Region of Durham Works Department, a partnership with three

local builders – Brookfield Residential, Halminen Homes, and Jeffery Homes – has led

to the completion of six demonstration homes, two constructed per builder. These

homes were designed to incorporate water and energy improvements (“green

practices”), with the goal of reducing the home’s environmental impact beyond the

efficiency parameters set out by the OBC 2012.

The GDP set energy and water conservation targets based on the OBC 2012 and future

legislated efficiency increases. For energy efficiency, the GDP is aiming to achieve 15%

improvement over 2012 new homes, in advance of the January 1, 2017 update to the

OBC. To determine its water efficiency goals, the GDP looked at past improvements to

the OBC as well as current technological advances, choosing a target of 15% increase

in water efficiency over the OBC 2012 requirements. This translates to a goal of 130

L/person/day (LCD) consumed in a residential setting. The current Region-wide

consumption average is 230 LCD4.

Detailed 12-month monitoring of the electricity and water consumption of each

demonstration home, referred to as the “As-built” home, was used to assess the

performance of the green practices in “real use” settings. This performance was

compared to an equivalent home, referred to as a “Code-built” home, which has instead

been designed to the minimum efficiency standards required by the OBC 2012. Sub-

meters were used to measure the consumption of individual appliances and water

fixtures, in addition to whole-home utility meter readings.

4 Residential basic usage (i.e. non-seasonal) for the Region of Durham in 2015 was 230

m3/customer/year (Regional Municipality of Durham 2016 Water and Sanitary Sewer User Rates Detailed

Report, Joint Finance & Administration and Works Committee Report #2015-J-59, December 3, 2015). A

value of 2.75 people per household has been assumed, based on 2016 Region of Durham projections

(Growing Durham, May 2008).


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The water and energy consumption data was used to quantify the efficiency

improvements of the various green practices and greenhouse gas avoidance. In

addition, financial analyses was performed to demonstrate return on investment

compared to conventional building design. The results of this project can be used to

inform the development of future OBC requirements, by identifying successful and cost

effective green practices. It also helps to inform the home building industry and home

buyers of water and energy efficient equipment, materials and technologies.

2.4 Participant and Home Overview

All of the project participants were interviewed at the start of the GDP to assess their

lifestyle characteristics, the number of full-time occupants within the home, and

household water and energy conservation approaches. This data is important for the

purposes of correlating monitored data, informing inputs for modelling and

understanding the results, for such key performance indicators such as liters per capita

per day of water consumption and annual energy intensity per capita.

The six homes in the GDP were all single-family residences, built in 2014; two were

townhouses, and four were single detached homes. The average floor area was 2,400

ft2 (224 m2), and number of occupants ranged between 2 and 4 persons.

Table 4 – GDP Home Overview

Home ID # of occupants Area (m2)

Area (ft2)

A 3 191 2,055 B 3 142 1,528 C 2 145 1,560 D 4 252 2,712 E 4 189 2,034 F 4 276 2,970


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3.0 Monitoring Program

Prior to occupancy, sub-meters were installed in each of the demonstration homes,

measuring electricity and water consumption of a variety of appliances and water

fixtures. These sub-meters, in combination with whole-home utility meters, were used to

identify the energy and water savings which are related to the implementation of green

practices. Natural gas was tracked using only the whole home utility meter for each

home. The monitoring period was for a full year, from November 1, 2014 to Oct. 31,

2015.

The sub-metered data included a range of electrical loads as well as water fixtures; sub-

metering was not necessarily the same for the six demonstration homes due to

constraints or differences in their construction, builder preferences, and/or the needs of

the occupants. The breakdown of sub-meters within each house is outlined in the table

below.

A full list of metered and derived data, outlining the source and reporting frequency, can

be found in Appendix B.

Table 5 – Sub-meters by GDP Homes

Sub-meter A B C D E F

Electricity

Air Conditioner Y Y Y Y N Y

Clothes Dryer Y Y Y Y Y Y

Energy Recovery Ventilator Y N N Y Y Y

Furnace Y Y Y Y Y Y

Greywater Recycling System Y N N Y N Y

Refrigerator Y Y Y Y Y Y

Washing Machine N Y Y Y Y Y

Water

Drain Water Heat Recovery System Y Y Y Y Y Y

En-suite Shower Cold Y N Y Y Y Y

En-suite Shower Hot Y N Y Y Y Y

Greywater Recycling System Make-Up Water Y N N Y N Y

Greywater Recycling System Toilet Flush Water Y N N Y N Y

Hot Water Recirculation System Y N N N Y N

Kitchen Faucet Cold Y Y Y Y Y Y

Kitchen Faucet Hot Y Y Y Y Y Y

Washing Machine Cold Y Y Y Y Y Y

Washing Machine Hot Y Y Y Y Y Y


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Based on the amount of data currently available regarding the water savings associated

with installing efficient toilets, toilet sub-metering was omitted from the GDP. Other

water uses within the participating homes, such as lavatory faucets and dishwashers,

were not monitored primarily because the associated demands are very small.

3.1 Electricity Sub-metering

Electricity sub-metering was achieved using a Triacta PowerHawk 4325 High Density

Building Automation Meter coupled to QMC Metering Solutions’ MeterConnex web

portal and reporting system. The PowerHawk unit was set up for demand interval sub-

metering in 60 minute time periods. Since the PowerHawk connects directly to the

home’s main circuit panel, certain appliances had to be plugged into specific outlets to

be correctly perceived by the system.

Detailed information about the installed sub-meters can be found in Appendix C.

3.2 Water Sub-metering

Water sub-metering was achieved using an Obvious AcquiSuite DR data acquisition

server which was also coupled to QMC Metering Solutions’ MeterConnex web portal

and reporting system. The AcquiSuite sub-metering unit provides easy wireless

connectivity to the pulse water sub-meters installed within the homes.

The two types of pulse water sub-meters installed had different resolutions, 10 L and

37.85 L; this means that an electrical pulse is recorded every time 10 or 37.85 L flows

through the sub-meter. The data acquisition server multiplies the number of pulses

received in each 15 minute interval by the sub-meter’s multiplier to determine the total

consumption (in litres) within that time interval.

Detailed information about the installed sub-meters can be found in Appendix C.

3.1 Gas Metering

Gas monitoring consisted of monthly readings of the utility meter. The furnace energy

was not separately metered from the domestic hot water heater, but the amount of hot

water called to the domestic hot water heater was measured.


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4.0 Annual Energy and Water Consumption Modelling

Energy modelling is the process of creating a computerized model of a building design

to estimate its operational annual energy consumption; furthermore, it enables the

comparison of various energy conservation measures in terms of energy and cost

savings. The energy modelling software used in this project is HOT2000 (Version

10.51), provided by the CanmetENERGY branch of Natural Resources Canada

(NRCan).

Most energy modelling is completed during the design phase of home construction and

uses anticipated consumption values derived from industry averages. For the GDP,

however, modelling was performed using inputs that are derived from the actual

measured consumption from the home. As a result, these GDP models more accurately

reflect the actual occupant consumption behaviour.

As there is only a limited water component to the HOT2000 software that determines

domestic water heating energy consumption, annual water consumption is modelled

separately with spreadsheet analysis. The HOT2000 water modelling would typically be

based on industry expected consumption schedules, however, the monitoring

component of the GDP allows all water modelling to be based on actual water

consumption data, improving accuracy. Inclusion of water modelling is unique in

comparison to standard industry energy modelling practices. The energy savings

related to water consumption avoidance are typically realized to the greater extent by

the water service provider, in this case the Region, through reduced pumping and

treatment needs rather than the homeowners. The more significant benefit to

homeowners is realized through lower water utility bills.

As mentioned, "As-built" homes are the actual GDP homes which have had green

practices implemented in their design and construction, and are being sub-metered. A

"Code-built" home refers to a dwelling which was designed strictly in accordance to

compliance package J from Supplementary Standard SB-12 of the OBC (see further

explanation under Section 4.2 below). Since each of the six GDP homes have a

different footprint, each one has an equivalent “Code-built” dwelling modelled with

matching architectural geometry. The characteristics of these “As-built” and “Code-built”

homes in terms of the GDP are defined in the following sections.

A comprehensive analysis of the methodology for the energy and water consumption

modelling inputs is available in Appendix D.


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4.1 As-Built House Descriptions

The definition of an As-built dwelling varies amongst the GDP homes, based on which

green practices were implemented by the home builder. In general, green practices

include appliance and fixture efficiency upgrades, as well as envelope and mechanical

equipment improvements beyond OBC requirements. The impact of envelope and

mechanical equipment efficiency upgrades is not directly measurable (i.e., by sub-

metering), however, modelling for each house takes into account how these green

practices affect energy and water consumption. Some examples of these indirectly

measurable green practices include the use of exterior insulated sheathing, minimized

air leakage, and increased furnace efficiency.

For the As-built homes, all the energy and water consumption values, which are

required as inputs for modelling, have been obtained from the monitoring results. The

electrical consumption of all metered applications is averaged over the reporting period

to provide a daily value in kilowatt hours per day (KWh/day). With regard to water, the

manual modelling method is based on OBC water fixture flow rate values in comparison

to the fixtures which were actually installed in the As-built homes.

The table in Appendix E outlines the GDP green practices, and notes in which homes

they are implemented.

4.2 Code-Built House Descriptions

The envelope and mechanical equipment characteristics of a Code-built dwelling were

drawn from the Supplementary Standard SB-12: Energy Efficiency for Housing of the

Ontario Building Code; specifically, Compliance Package J of the prescriptive

compliance method. Supplementary Standard SB-12 outlines the energy efficiency

requirements, standards, and procedures for homes constructed under the OBC 2012.

Compliance Package J was chosen as the best representation of a Code-built home

based on the features of the GDP homes, and as the compliance package most

commonly used by local builders in Clarington.

Not all modelling inputs were prescribed in Compliance Package J, as such, various

plug loads within the house were assumed to be equal between the Code-build and As-

built homes – these included: major appliances, lighting, and plug loads. Furthermore,

and as per SB-12’s performance compliance modeling guidelines, all Code-built homes

are modelled with 16” on centre stud spacing.

Details of this compliance package are available in Appendix F.


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5.0 Actual and Annualized Results

5.1 Monitored Results

5.1.1 Total Monitored Electricity Consumption by Sub-meter

This section documents electrical consumption by end-use, and specifically focuses on

the sub-metered appliances within the homes. Since consumer electronics and lighting

were not sub-metered, these categories are combined to the ‘Other Electrical Loads’

category. The table below outlines the sub-metered electrical consumption by end-use

in kilowatt hours (kWh).

Table 6 – Monitored Electrical Consumption by End-Use

A B C D E F Average

# of Persons per Household

3 3 2 4 4 4 3.3

Sub-meter kWh kWh kWh kWh kWh kWh kWh

Air Conditioner 128 292 632 552 - 1,032 527

Dryer 663 475 439 513 464 788 557

Energy Recovery Ventilator

468 - - 625 33 1,044 543

Furnace 639 1,147 978 1,712 518 691 948

Greywater Recycling System

11 - - 19 - 14 15

Refrigerator - 296 268 586 451 444 409

Washing Machine - 39 20 23 50 38 34

Other 4,308 2,660 2,278 4,334 7,200 3,352 4,022

Whole Home 6,217 4,909 4,615 8,364 8,716 7,403 6,704

Average (kWh/month) 518 409 385 697 726 617 559

5.1.2 Total Monitored Water Consumption by Sub-meter

This section focuses on indoor water consumption by end-use and does not include any

sub-meters which would lead to double counting of water consumption, for example –

drain water heat recovery system, greywater supplied to flush toilets, and hot water

recirculation system. Removing these sub-meters allowed for the data to be presented

as a percentage of the whole home use. The table below outlines the water

consumption by end-use in litres (L).


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Table 7 – Monitored Water Consumption by End-Use (L)

A B C D E F Average

# of Persons per

Household 3 3 2 4 4 4 3.3

Sub-meter L L L L L L L

En-Suite Shower Hot 18,850 - 79,990 15,990 10,420 54,900 36,030

En-Suite Shower Cold 10,900 - 8,710 2,730 4,580 6,690 6,722

Greywater Make-Up H2O 9,320 n/a n/a 23,010 n/a 6,660 12,997

Kitchen Faucet Hot 29,939 35,617 10,106 14,610 10,749 - 20,204

Kitchen Faucet Cold 28,615 8,176 1,703 2,157 3,369 4,466 8,081

Washing Machine Hot 3,040 970 2,890 2,440 680 680 1,783

Washing Machine Cold 17,900 9,460 13,010 10,480 17,460 14,360 13,778

Other 61,715 152,101 19,249 44,098 55,144 58,709 65,169

Whole Home 180,279 206,324 135,658 115,515 102,402 146,465 147,774

LCD 165 188 186 79 70 100 131

5.1.3 Total Natural Gas Consumption

Total natural gas consumption for each of the GDP homes was determined by reading

the utility meter situated on the exterior of each home on a monthly basis. Natural gas

sub-metering within the GDP homes was not feasible based on financial, regulatory,

and logistical considerations. The table below summarizes annual natural gas

consumption for the GDP homes during the 12 month monitoring period.

Table 8 - Annual Natural Gas Consumption by Home

Home ID Annual Natural Gas Consumption

m3 kWhe

A 2,239 23,733

B 2,125 22,525

C 2,163 22,928

D 1,544 16,366

E 1,550 16,430

F 1,118 11,851

Average 1,790 18,972


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5.2 Modelling Results

The modelled results presented in Tables 9 and 10 below are for one year, and are

based on the data collected during the GDP monitoring period2. Full modelling results

can be found in Appendix G.

Annual costs were derived using the following prices and reference rate estimation

tools:

Electricity – Ontario Energy Board Residential Customer Utility Bill Estimation Tool

o Utility: Hydro One Networks Inc.

o Service Area: Residential – Urban (UR)

o Pricing Plan: Time-of-use – Off-peak: 64%, Mid-peak: 18%, On-Peak: 18%

o Rate: $0.20/kWh; based on average monthly consumption of 800 kWh

Natural Gas – Ontario Energy Board Residential Customer Utility Bill Estimation

Tool

o Utility: Enbridge Gas Distribution Inc.

o Rate: $0.397/m3; based on average monthly consumption of 283 m3

Water – Regional Municipality of Durham 2015 Water and Sanitary Sewer User

Rates

o $0.944 per cubic meter of water supply

o $1.603 per cubic meter for sanitary sewer usage

o Monthly water service charge: $15.86

o Monthly sanitary sewer usage charge: $6.28

o Rate: $3.645/m3; based on average quarterly consumption of 60m3

Based on a comparison to the Code-built homes, the As-built demonstration homes

show annual energy savings ranging from 9% to 12%, and annual cost savings ranging

from $98 to $624, for an average of 10% energy savings and $260 in cost savings for

the six homes.

The annual water savings, for homes without greywater recycling systems, ranged from

8% to 12% with annual savings ranging from $31 to $72; this category of home

averaged 10% reduction in water use relative to OBC 2012 and average annual savings

of $57. For homes with a greywater recycling system installed, the water savings were

more substantial; in this category, water reduction was about 20% with annual savings

ranging from $98 to $162 for an annual average of $128.


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Table 9 – Annual Modelled Energy Consumption

Home ID

Annual Modelled Energy Consumption (kWhe)

Annual Modelled Energy Cost ($)

Code-Built As-Built Energy Savings

% Better Than

OBC 2012 Code-Built As-Built

Cost Savings

A 39,494 35,638 3,856 10% $3,765 $3,605 $160

B 31,896 29,026 2,870 9% $3,278 $3,168 $110

C 33,804 30,146 3,658 11% $3,339 $2,933 $405

D 41,677 36,819 4,858 12% $786 $688 $98

E 36,863 33,415 3,558 9% $4,410 $4,225 $185

F 47,792 42,105 5,687 12% $5,811 $5,186 $625

Total 231,636 207,149 24,487 - $21,390 $19,806 $1,584

Average 38,606 34,525 4,081 11% $3,565 $3,301 $264

Table 10 – Annual Modelled Water Consumption

Home ID

Annual Modelled Water Consumption (L)

Annual Modelled Water Cost ($)

Code-Built As-Built Water

Savings

% Better Than OBC

2012 Code-Built As-Built

Cost Savings

A 224,601 180,279 44,322 20% $1,086 $924 $162

D 142,460 115,516 26,944 19% $786 $688 $98

F 180,105 146,465 32,966 19% $924 $784 $123

Average - With

Greywater Recycling

182,388 147,420 34,968 19% $932 $804 $128

B 226,029 206,323 19,706 9% $1,092 $1,020 $72

C 154,276 135,657 18,619 12% $829 $761 $68

E 111,005 102,402 8,603 8% $671 $640 $31

Average – No

Greywater Recycling

163,770 148,127 15,643 10% $864 $807 $57

Total 1,038,476 886,642 151,834 - $5,389 $4,834 $555

Average 173,079 147,774 25,306 14% $898 $806 $92


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6.0 Analysis

The modelled results based on one year’s monitored data were used to demonstrate:

energy use intensity, energy use per capita, water use intensity, water use per capita,

and greywater system efficiency. In addition, an analysis of greywater quality was

completed based on the results of periodic greywater sampling undertaken by the

Region during the GDP monitoring period.

6.1 Energy Use Intensity

Energy use intensity (electricity + natural gas) is a key metric used to compare the

energy consumption of a building relative to its size. Energy intensity per capita is a

metric which sheds light on the human behaviour in the buildings; it demonstrates that

energy efficient appliances and equipment also need to be used in an energy

conserving manner. In both cases, a lower number represents more efficient energy

use, whether it is through design or human behaviour.

From Table 11, it can be seen that energy intensity for the As-Built homes saw a 10%

reduction compared to the Code-Built homes. This level of reduction in energy intensity

was observed amongst all the homes. Since the energy modelling methodology tried to

maximally reduce the impact of human behaviour variance on the energy consumption

of the home, we can infer that these results are a reflection of the improved envelope

characteristics such as: improved insulation, improved air tightness, better workmanship

in insulation installation, duct sealing, etc.


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Table 11 – Energy Use Intensity

Co

de

-Bu

ilt

Home ID

Total Annual Energy Consumption

Energy Intensity Energy Intensity

per Capita

(kWhe) (kWhe/m2/yr) (kWhe/m2/yr/person)

A 39,494 207 69

B 31,896 225 75

C 33,804 233 117

D 41,677 165 41

E 36,863 195 49

F 47,792 173 43

Average 38,588 200 66

As

-Bu

ilt

Home ID Total Annual Energy

Consumption Energy Intensity

Energy Intensity per Capita

(kWhe) (kWhe/m2/yr) (kWhe/m2/yr/person)

A 35,638 187 62

B 29,026 204 68

C 30,146 208 104

D 36,819 146 37

E 33,415 177 44

F 42,105 153 38

Average 34,525 179 59

6.2 Water Use Intensity

Water use intensity is a key metric used to compare the water consumption of a building

relative to its size. Water use per capita demonstrates the water consumption behaviour

of the occupants. Similar to energy intensity per capita, it demonstrates that water

efficient appliances, fixtures and faucets also need to be used in a water conserving

manner. In both cases, a lower number represents more efficient water use, whether it

is through design or human behaviour. From Table 12, it can be seen that water use

intensity for the As-Built homes was reduced by roughly 14% relative to Code-Built

homes. Isolating only the homes which have a greywater recycling system installed, the

average water use intensity decreased by 18% in the As-built homes relative to the

Code-built homes; comparing only the homes which did not have a greywater recycling

system installed, the average water use intensity decreased by 11% in the As-built

homes relative to the Code-built homes.


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Table 12 - Water Use Intensity

Co

de

-Bu

ilt

Home ID

Total Water Consumption

Water Use Intensity

Average Daily Water

Consumption

Daily Liters per Capita

L L/m2/yr L/day LCD

A* 224,601 1,176 646 215

B 226,029 1,592 619 206

C 154,276 1,064 423 211

D* 142,460 565 390 98

E 111,005 587 304 76

F* 180,105 653 479 120

Average 173,079 939 474 153

As

-bu

ilt

Home ID

Total Water Consumption

Water Use Intensity

Average Daily Water

Consumption

Daily Liters per Capita

L L/m2/yr L/day LCD

A* 180,279 1,003 525 175

B 206,323 1,453 565 188

C 135,657 936 372 186

D* 115,516 458 316 79

E 102,402 542 281 70

F* 146,465 514 389 97

Average 147,744 811 405 131 * GDP Homes with a greywater recycling system installed

6.3 Greywater Recycling System Efficiency

Three of the GDP homes were outfitted with greywater recycling systems, which were

fed by two shower fixtures on the upper floors, and provided water for toilet flushing.

Although the technology is still in its infancy, and trials and improvements are ongoing,

these units provide the potential for significant water consumption avoidance.

The greywater recycling systems have municipal potable water connected to them as a

secondary means of toilet flushing in case there is a shortage of greywater

accumulation. Table 13 outlines the observed efficiency of each unit installed for the

GDP. The ‘Potable Water Consumption Avoided’ column represents the amount of

greywater used for toilet flushing. In the absence of the greywater recycling system,

this quantity of water would have come from the clean municipal potable water supply.

The closer the ‘Potable Water Consumption Avoided’ figure is to the ‘Greywater to

Toilets’ figure, the more efficient the system operation is; the difference is made up by

potable water in the ‘Potable Make-up Water’ column.


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Table 13 – Greywater Recycling System Efficiency

Home ID

Potable

Make-up

Water

Greywater

to Toilets

Potable Water

Consumption

Avoided

Efficiency Avoidance per

Capita

L L L % LCD

A 9,320 22,830 13,510 59% 12.3

D 23,010 39,600 16,590 42% 11.4

F 6,660 28,830 22,170 77% 15.2

Average 12,997 30,420 17,423 59% 13.0

Although packaged greywater recycling systems are in their infancy, and further

refinement is required, the potential water savings realized through the implementation

of this technology is undeniably significant. As the above table illustrates, the average

annual water avoidance of a home outfitted with a greywater recycling system was

17,423 liters. Factors effecting greywater system efficiency may include:

Filter clogs which divert greywater away from the tank storage and into the

sanitary sewage drain; and

Purge frequency which may purge the accumulated greywater before it is used

for flushing

During the course of the GDP, two of the greywater recycling systems had their purge

frequencies refined in order to increase their efficiencies. The systems come pre-

programed with a 48 hour purge cycle; this ensures that if greywater goes unused for a

period of 48 hours, it is automatically purged to the sewer drain in order to maintain

optimal freshness in the tank. Given that these units were prototypes, the 48 hour purge

frequency was a conservative setting until real-world system operation was better

understood.

While it is vital to maintain the freshness of the water in the tank, it is important to

balance that requirement with system efficiency. While keeping track of the system

efficiency, Sustainable EDGE noticed that one of the systems was underperforming

relative to the others. A possible reason for this complication was a mismatch in purge

cycling timing relative to occupant shower habits – it is important to time the purge

cycles to regularly occur before a likely shower event in order to replenish the tank with

greywater rather than fresh potable water. Since not all households have predictable

shower habits, this can be difficult to achieve.


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After changing the timing of the purge cycles failed to produce better system

efficiencies, the units in two of the homes had their purge cycles extended to ten days

rather than the default 48 hours. The following analysis examines the efficiencies of

these two greywater systems before and after their purge cycle shift.

Table 14 - Effects of Purge Frequency on Greywater System Efficiency

Home ID

Start Date

End Date

Purge Frequency

Grey Water to

Toilet

Potable Make-

Up Water

Avoidance

Efficiency

Avoidance per

Capita

L L L % LCD

D 11/01/14 07/28/15 48 hours 29,090 21,200 7,890 27% 7

07/29/15 10/31/15 10 days 10,510 1,810 8,700 83% 23

F 11/01/14 07/10/15 48 hours 18,940 4,390 14,550 77% 14

07/11/15 10/31/15 10 days 9,890 2,270 7,620 77% 17

The data above shows that reducing the purge frequency had a substantial effect on the

efficiency of one of the greywater systems. Furthermore, no qualitative decrease in

water quality was observed by the occupants and the owners of the two units tested

above were very happy with their performance. If water quality becomes an issue in the

future, the purge frequency can be further adjusted to maintain the balance between

water quality and system efficiency.

The observed savings attributed to the greywater recycling systems have significant

potential implications for the Region. These potential savings are two-fold in that they

spend less money on pumping and treating less water annually, and the avoided water

consumption may allow the Region to defer investment of new water treatment

infrastructure as current infrastructure is able to handle the smaller loads being

connected to it. Infrastructure savings have the potential to be significant in growing

municipalities like Clarington and the greater Durham Region. Refer to Section 7 –

Financial Assessment for a more in-depth financial analysis of the greywater recycling

system as it relates to home owners, and Section 12 – Overall Findings,

Recommendations, and Lessons Learned for a more in-depth analysis of the potential

impact to the Municipality and the Region.

6.4 Greywater Recycling System Water Quality Testing

Between October 1, 2014 and October 31, 2015 a sampling program was conducted by

the Region to monitor greywater quality. Samples were taken from a dedicated

sampling port between the discharge of the greywater recycling systems and the


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toilets. Results were compared to Health Canada’s Canadian Guidelines for Domestic

Reclaimed Water for Use in Toilet and Urinal Flushing (January 2010) (DRW Guideline),

which provides water quality targets that can be used to maintain an acceptable quality

of reclaimed water. DRW Guideline parameters monitored included Biological Oxygen

Demand (BOD5), Total Suspended Solids, E.coli and Total Chlorine Residual. In

addition, the Region added several parameters to the sampling program to achieve a

better overall understanding of the water quality, including Total Coliforms,

Heterotrophic Plate Count and pH.

Lab results indicated that most samples did not meet DRW Guideline values for Total

Suspended Solids. Several samples did not meet DRW Guideline values for Total

Chlorine Residual, which may have resulted in an increase of Total Coliforms and

Heterotrophic Plate Count. One sample for E.coli did not meet DRW Guideline values

and may be attributed to loss of disinfection due to operator error. Following the change

in greywater recycling system purge frequency for two of the units, from every 48 hours

to every ten days, subsequent greywater samples indicated an increase in Total

Coliforms and Heterotrophic Plate Count values; this may be attributed to the increased

greywater holding time. Given that the greywater was being sent to the household

toilets for flushing, homeowner exposure was very limited.

The Region’s complete Residential Greywater Sampling Program report, including

detailed lab results for the three monitored greywater recycling systems, is provided in

Appendix H.


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7.0 Financial Assessment

7.1 Methodology

Various energy and water green practices were identified and a financial analysis was

performed on the following:

Energy

Building envelope and heating, ventilation and air conditioning (HVAC) energy conservation measures (bundled)

Domestic hot water (DHW) heater

Water

En-suite shower faucet

Kitchen faucet

Greywater recycling system

Ultra-low flow toilets

In addition to the above list, a financial assessment of the whole home, encompassing

all the green features, was performed. The above list was chosen based on available

sub-metered data which allowed for a financial analysis based on operational cost

savings. The building envelope and HVAC are bundled because these features act as

one unit and it is not possible to single out their individual contributions to the overall

energy efficiency of the home; therefore, all of the space heating and cooling savings

realized by the GDP homes are credited to the overall improved envelope and HVAC

package. The financial analysis methods for each feature included simple payback and

net present value (NPV). Detailed analysis is presented in Appendix J.

7.1.1 Simple Payback

Simple payback is the number of years it takes to recoup a premium on an investment

through realized operational cost savings in the first year. In the context of the GDP, the

simple payback of the various energy and water efficiency upgrades were assessed

based on first year energy and/or water cost savings.

7.1.2 Net Present Value

The NPV is defined as the difference of the present value for two options with regard to

incoming and outgoing cash flows over a period of time. Time value of money dictates

that time has an impact on the value of future cash flows, and therefore the discount

rate and price escalation rate(s) must be factored into these future cash flows to

accurately assess the value of an investment in today’s dollars. Due to its relative


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simplicity, NPV is a useful tool to determine whether a project or investment will result in

a net profit or loss; a positive NPV results in profit, while a negative NPV results in a

loss. In the case of the GDP, energy and water conservation features typically have an

incremental cost, seen as a cash outflow, but also result in cost savings over the life

span of the feature, seen as annual cash inflows. These operational cost savings are

tabulated over the life span of the feature to evaluate its profitability.

This NPV analysis compares the As-built cases with the Code-built base cases by

bringing 20 years’ worth of capital and energy/water expenditures to the present dollar

value. The current worth or present value of future dollars is discounted at a specified

rate. This discount rate is based on the following factors. The first factor is that if the

capital costs were invested in the banks, it is assumed that they would yield a yearly 4%

return. Secondly, it is assumed that the purchasing power of today’s dollar reduces

every year at 2% per year due to the cost of inflation. If we take the 4% possible return

and subtract the cost of inflation we are left with a 2% yearly gain. Therefore, the

discount rate used in this analysis will be 2%, to conservatively represent a better

investment than simply investing the same money in the bank.

7.2 Escalation Rates

7.2.1 Electricity

Sustainable EDGE analyzed historical electricity prices going back to May of 2006.

Time of use rates, delivery, and transmission charges were all factored into the

analysis; all calculations are based on an average monthly residential electricity bill of

800 kWh. The following chart outlines average annual historical escalation rates in

electricity prices within Ontario – it is based on the pricing structure set out by the

Ontario Energy Board.

Table 15 – Historical Annual Electricity Rate Escalation

Time Period Average Annual Electricity

Price Escalation Rate

2012 – 2015 6.70%

2010 – 2015 5.70%

2006 – 2015 4.80%

Taking these historical escalation rates into account, Sustainable EDGE concludes that

the average annual escalation rate of electricity prices over the next 20 years is 6%.


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This escalation rate will form the basis of the electricity cost escalation for the GDP

financial assessment.

7.2.2 Natural Gas

Natural gas is a commodity whose price is notoriously volatile and therefore hard to

forecast beyond the near term. As such, price projections beyond a three year time

span represent approximations of the expected price. Based on the New York

Mercantile Exchange (NYMEX), the price of natural gas is forecast to increase at an

average rate of 3% annually until 2019. In Ontario, the natural gas prices are set by the

Ontario Energy Board. Past prices of natural gas, going back to 2011, indicate an

escalation rate approaching 2%. Since the price of natural gas is so volatile, and prices

are currently at a low, an escalation rate of 3% was applied to natural gas.

7.2.3 Water

The Regional Municipality of Durham 2016 Water and Sanitary Sewer User Rates

Detailed Report (Report #2015-J-59, December 3, 2015) (Committee, 2015) estimates

that the combined water and sewer user rate increase will be approximately 5% to 7%

per year over the forecast period 2017 to 2025, depending on future customer growth,

water demand and financial planning decisions. Accordingly, for the purposes of

financial analysis of water conservation features within the GDP homes, Sustainable

EDGE used an annual water escalation rate of 6%.

7.3 Financial Assessment Results

The financial analysis is based on a few factors which vary amongst the green

practices, such as, commodity cost, capital cost, installation cost, maintenance costs,

realized savings, lifespan of the feature, and lifespan of the financial study; these are

summarized here for clarity. In all cases, the average costs which would be incurred by

the builders or homeowners was used. The savings are based on the average of the

GDP homes. A discount rate of 2% was applied for all NPV analyses.

Commodity Prices

The following commodity prices are used within the financial analysis.

Commodity Price Escalation Rate

Water $ 3.65 m3 6%

Natural Gas $ 0.40 m3 3%

Electricity $ 0.20 kWh 6%


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Ensuite Shower Faucet:

Capital cost: $50, this is the incremental cost of a low-flow shower faucet based on

local retail prices available to the consumer.

Estimated life of faucet: 10 years

Span of financial analysis: 20 years

Annual water savings: 6.4 m3; based on average calculated water avoidance amongst

the six GDP homes due to using a low-flow (6.6 L/min) shower head relative to the

maximum flowrate allowed by OBC (7.6 L/min)

Assumed annual maintenance cost: $0

Kitchen Faucet

Capital cost: $170, this is the incremental cost of a low-flow kitchen faucet of the

variety used in this study; it is based on local retail prices available to the consumer.

Estimated life of faucet: 15 years


Annual water savings: 11.3 m3; based on average calculated water avoidance

amongst the six GDP homes due to using a low-flow (5.7 L/min) kitchen faucet relative

to maximum flowrate allowed by OBC (8.35 L/min)


Greywater Recycling System

Capital cost: The capital cost of this green practice is broken into unit cost and

installation cost. Installation is factored in because the unit is not a standard feature

which the builders usually include and therefore the extra labour and material cost must

be factored in.

Unit Cost: $2,500 + HST = $2,825

Installation Cost: $1,000 (details in appendix J).

Estimated life of unit: 20 years


Annual water savings: 17.5 m3; based on average measured water avoidance

amongst the six GDP homes due to harvesting of greywater for toilet flushing purposes.


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Assumed annual maintenance cost: $20 ($17 for chlorine and unit maintenance, $3

for pump electricity).

Low-Flow Toilets

Capital cost: The incremental cost of an ultra low-flow toilet is estimated at $65. Pricing

varies by manufacturer and model, therefore an average of costs was taken amongst

popular models. It is based on local retail prices available to the consumer.



Annual water savings: 8 m3; based on average calculated water avoidance amongst

the six GDP homes due to utilization of ultra low-flow toilets. This value is based on an

average of 14 toilet uses per household per day (Dziegielewski, 2014), with a 50%

penetration of dual-flush toilets (1.9/3.8 LPF) and the rest of the toilets being regular

ultra low-flush (3.8 LPF) as compared to maximum code allowed of 4.8 LPF. For the

dual flush toilets, 5 full flushes and 9 half flushes were assumed.


Upgraded DHW Heater

Capital cost: The incremental cost of the upgraded DHW heats is estimated at $400

based on pricing available to consumers. In reality, these units are actually rented by

the home owner so they do not experience the full incremental cost up front. This

analysis is done for illustrative purposes and is not indicative of the cost savings actually

experienced by the GDP participants.



Annual natural gas cost savings: $64; based on average savings as modelled using

HOT2000 energy modelling software and is based on actual sub-metered data of total

hot water consumption for the homes within the GDP.


Envelope & HVAC

Capital cost: $3,000; this is the average incremental cost incurred by the builder to

include the non-standard green practices such as: attic insulation and basement

insulation upgrade, advancing framing, insulated sheathing, better air sealing, etc.


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These green practices vary by builder and this analysis is done as an average cost

incurred by the builders.



Annual electricity cost savings: $165; taken as the average savings as modelled

using HOT2000 energy modelling.

Annual natural gas savings: $57; taken as the average savings as modelled using

HOT2000 energy modelling.

Assumed annual maintenance cost: $0; No incremental maintenance or operational

cost is attributed to the building envelope because it is assumed the same operational

cost would apply to both the Code-built and As-built cases.

Whole Home

Capital cost: $7,150; this is the average incremental cost incurred by the builder to

include all non-standard green practices (water & energy) as outlined in Appendix E.



Annual electricity cost savings: $165; taken as the average savings as modelled


Annual natural gas cost savings: $57; taken as the average savings as modelled


Annual water cost savings: $92; taken as the average savings as modelled by

Sustainable EDGE.

Assumed annual maintenance cost: $0; No incremental maintenance or operational

cost is attributed to the building because it is assumed the same operational cost would

apply to both the Code-built and As-built cases.

The table below outlines the simple payback and the NPV of each of the green

practices applied within the GDP; detailed financial analysis is provided in Appendix J.


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Table 16 - Financial Analysis Summary

Green Practice Simple

Payback Net Present

Value

Years $ (2015)

Envelope and HVAC Energy Conservation Measured (Bundled)

13.5 $ 3,065.00

DHW Heater 6.3 $ 990.00

En-suite Shower Faucet 2.1 $ 586.00

Kitchen Faucet 4.2 $ 896.00

Greywater Recycling System 60 $ (2,200.00)

Ultra-Low Flow Toilets 2.1 $ 785.00

Whole Home 22.8 $ 1,660.00

The financial analysis performed on the water saving features of the GDP yielded very

positive results for a number of green practices, such as low flow faucets and ultra-low

flow toilets which achieved a positive net present value in our analysis. This indicates it

is a good investment to make when purchasing a home. The greywater recycling

system technology failed to achieve a positive NPV over the span of a 20 year analysis.

As this emerging technology matures, it is expected to achieve greater market

penetration, which may have a positive effect on future NPV evaluations as economies

of scale take effect and drive system prices down. On the energy side of green

practices, all the upgraded features assessed achieved a positive NPV and are deemed

investment worthy for the homeowner.

Secondary Financial Analysis of Greywater Recycling System

A secondary financial analysis of the greywater recycling system was undertaken

wherein the higher efficiency of the ten day purge cycle is applied to the whole year to

evaluate if the cost savings make the unit more financially viable. While the increased

annual efficiency saves the homeowner more money per year, the NPV remains

negative. The findings are:

As tested in GDP; simple payback: 60 years, NPV: -$2,200;

Secondary analysis with annual efficiency of 80%; simple payback: 43.2 years,

NPV: -$1,500.

Extending the purge cycle to ten days, and thus allowing the greywater recycling system

to operate at higher efficiencies, increased the NPV of the system by roughly $700;

unfortunately, this did not tip the NPV into positive territory which would indicate an

investment worthy feature. As this technology matures it is expected to achieve greater


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market penetration leading to economies of scale lowering the unit cost. In the future,

this system might be economically viable for the homeowner, but based on this

assessment this system currently does not pay itself off within its lifespan.


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8.0 Comparison of HERS Rating to EnerGuide Rating

The Home Energy Rating System (HERS) Index and NRCan’s EnerGuide Rating

System are both evaluation systems which provide an analysis of a home’s energy

efficiency and provide a numerical rating which allows for comparison between other

rated homes. Both systems are approved for use in the OBC. Each rating system takes

into account the physical characteristics of the home in order to assess how the home

itself uses energy, while trying to minimize the variable behavioural factors of its

occupants. Physical characteristics include the wall and window assembly R-values, air

tightness, and heating, cooling, and ventilation systems. The behavioural factors include

occupancy schedules, temperature set-points, amount of hot water used, and plug

loads and their duration of use.

The GDP completed a home energy rating on each demonstration home prior to

occupancy using the HERS Index. For the purposes of examining both rating systems

permitted by the OBC, the more commonly used EnerGuide rating was calculated using

as-operated data after a full year of monitoring. This description provides an overview of

both rating systems and demonstrates the application of rating systems prior to home

owner occupancy and based on actual living conditions.

Similar rating systems that provide an analysis of a home’s water efficiency are not

available.

8.1 Home Energy Rating System Index

The HERS Index measures the energy efficiency of a home using a comprehensive test

conducted by a certified CRESNET Home Energy Rater. This Index is the nationally

recognised system for inspecting and calculating a home’s energy performance in the

United States and it is also approved for such use in the province of Ontario. A series of

diagnostic tests, including blower-door testing and duct leakage are used as inputs to a

computerized simulation analysis using RESNET Accredited Rating Software; this

results in a rating score on the HERS Index.

The HERS Index places a score of 100 as a standard new construction building and is

based on the International Energy Conservation Code 2006; lower scores indicate

increased energy efficiency. Each percentage point above or below the standard new

construction score of 100 represents one percent of increased or decreased energy use

in the evaluated home, respectively. For instance, a score of 0 would indicate a net-zero

energy building. An average home built to OBC 2012 standards, following SB-12

Compliance Package J, would score 60 on the HERS Index.


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8.2 EnerGuide Rating System

EnerGuide is the official system for energy performance rating and consumer product

labelling in Canada. It presents a measure of a home’s energy performance based on

standard operation assumptions which enable comparison of one house against

another. An energy advisor analyses the house plans and uses HOT2000 energy

simulation software to determine the estimated annual energy usage and EnerGuide

rating; after construction the building is reviewed to verify the rating including a blower

door test.

EnerGuide ratings fall on a logarithmic scale between 0 and 100, with a higher score

indicating a more energy efficient home – for instance, a score of 100 indicates a net-

zero energy home. It is important to note that the EnerGuide scoring system differs from

HERS in that the points do not directly translate to a percentage improvement in energy

efficiency. In fact, due to the logarithmic nature of the rating scale the EnerGuide ratings

can fail to effectively communicate the comparative energy efficiencies of new homes.

This point is illustrated in the following two examples (Buchan, 2007):

1. On the lower end of the rating scale, the 13 point difference between a score of

67 and 80 actually represents a 50% reduction in relative energy for the higher

ranked home.

2. On the upper ends of the rating scale, the 6 point difference between a score of

80 and 86 still represents the same 50% reduction in relative energy use by the

more efficient home.

The table below shows a typical EnerGuide scoring structure with respect to energy

efficiency. An average home built to OBC 2012 standards, following SB-12 Compliance

Package J, would score an EnerGuide rating of approximately 75.

Table 17 – EnerGuide: Typical Energy Efficiency Ratings

Type of House Rating

New house built to provincial building code standards

65-69

Typical new house with some energy-efficiency improvements

70–74

Significantly upgraded energy-efficient new house

75–79

Highly energy-efficient new house 80–90

House requiring little or no purchased energy 91–100


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To address this issue, the EnerGuide Version 15, which is currently under development,

will forego the logarithmic 0-100 scale in favour of a consumption scale ranging from 0

GJ/year to infinity (Alberta Urban Municipalities Association, 2015).

8.3 HERS and EnerGuide in the GDP

At the start of the GDP, all six demonstration homes were analysed using HERS,

comparing the rating of the As-built homes to equivalent Code-built homes using OBC

2012 SB-12 Compliance Package J as the reference building inputs. Each home was

given a Code-built HERS rating as well as an As-built HERS rating. A summary of the

results are presented in the table below. The detailed methodology and evaluation are

provided in the “Priority Green Clarington – Green Demonstration Project Green

Practices Validation and Energy Modelling Final Report” (Clearsphere, January 2015)

found in Appendix K.

Table 18 – HERS Index Scores (Pre-Occupancy)

Home ID Code-Built HERS Index Score As-Built HERS Index Score

A 60 49

B 65 47

C 66 48

D 60 41

E 61 48

F 60 43

The HOT2000 modelling used in this report, which took into account the actual

performance of the GDP homes during the 12 month monitoring period (i.e. post-

occupancy), provided an EnerGuide rating for each house. Similar to the pre-occupancy

HERS evaluation, two ratings were tabulated per home to include the Code-built and

As-built cases. These EnerGuide numbers were not verified through on-site testing and

are presented for comparison only. The results of the post-occupancy EnerGuide rating

are shown in the table below.


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Table 19 – EnerGuide Ratings (Post-Occupancy)

Home ID Code-Built EnerGuide Rating As-Built EnerGuide Rating

A 75 76

B 78 79

C 76 77

D 76 78

E 74 76

F 74 76

Under both the pre-occupancy and post-occupancy scenarios and irrespective of the

rating system used, the difference in Code-built versus As-built scoring reflects the

increased efficiency gained by the GDP homes through the implementations of green

practices that exceed the minimum OBC requirements.

The methodology of the HOT2000 modelling included an assumption that the

appliances, which were chosen by the home owners, would be the same regardless of

the specifications of the house and therefore would be the same in both cases;

however, the same assumption was not applied in the HERS modelling. In order to

attempt a comparison between these two independent energy rating systems, it was

necessary to adjust the HERS ratings to a scenario in which the ‘Lighting and

Appliances’ loads are identical between the Code-built and As-built homes. Therefore,

the HERS As-built ‘Lighting and Appliances’ energy consumption value was applied to

the Code-built model in order to generate new “adjusted” HERS Index score.

The table below presents the adjusted HERS Index comparison of the Code-built and

As-built energy savings, as well as the post-occupancy comparison based on the

EnerGuide rating system.

Table 20 – Comparison of Rating System Savings Modelled HERS and HOT2000 Energy Consumption

Home

ID

HERS Index Score (Adjusted) EnerGuide Rating

Code-Built As-Built % Better

Than Code Code-Built As-Built

% Better

Than Code

A 54 49 10% 75 76 10%

B 57 47 17% 78 79 9%

C 59 48 19% 76 77 11%

D 55 41 25% 76 78 12%

E 56 48 14% 74 76 9%

F 54 43 21% 74 76 12%


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It is important to note that the HOT2000 energy modelling used real world sub-metered

energy and water consumption data from the homes as inputs and therefore provides a

summary of actual energy consumption. It is therefore not surprising that the actual

energy usage of the home deviates from the HERS model.


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9.0 Benchmarking of GDP Homes

Below, comparisons are provided between the energy and water consumption of the

GDP homes and typical homes in the neighbourhood and province.

9.1 Provincial Energy Benchmarking

In Table 21, the Code-built and As-built energy intensity results are compared to the

2012 Ontario average for new construction reported by NRCan (OEE, NRCan,

2012).The NRCan average should be reasonably representative as the large majority of

Ontario new house construction occurs in the Greater Toronto Area. While the value for

2012 was lower than the Code-built house average in the GDP, there is variation in the

NRCan data, and not necessarily a consistent trend of reduced energy use over time.

2010 demonstrated an average energy intensity value of 195 kWhe/m2/yr; for 2011 it

was 206 kWhe/m2/yr. Perhaps one could argue that the 2012 NRCan energy intensity

value of 188 kWhe/m2/yr means that builders are building, particularly in 2012, above

code on average and that the As-built homes are better than the average.

Table 21 - Ontario Benchmarking

Home ID

Code-Built Energy Intensity

As-Built Energy Intensity

Average Ontario New Construction Energy

Intensity (2012)

kWhe/m2/yr kWhe/m2/yr kWhe/m2/yr

A 207 187

188

B 225 204

C 233 208

D 165 146

E 195 177

F 173 153

Average 200 179 188

9.2 North American Water Consumption Benchmarking

The Water Research Foundation commissioned a report on residential water end use

titled: Residential End Uses of Water Study – 2014 (REUWS)5, which forms the basis of

this analysis. Various municipalities and water authorities across North America,

including the Region of Waterloo, Ontario, and the Region of Peel, Ontario set out to

study the end uses of residential water consumption and compile this data into a

5 The full report is not yet available; however, presentations on the topic have been released and are cited in this report.


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database for benchmarking and other analytical purposes. The following analysis

compares two metrics:

1. Household total water consumption per day

2. Household hot water consumption per day

Table 22, below, outlines the key performance indicators from that study and how they

compare to the GDP homes (Dziegielewski, 2014).

Table 22 - Indoor Water Use Benchmarking

Home ID

Indoor Water Use

Total Water Hot Water

LHD LCD LHD LCD

A* 494 165 252 84

B 565 188 319 106

C 372 186 267 134

D* 316 79 165 41

E 281 70 109 27

F* 401 100 258 65

GDP Avg. 405 131 228 76

REUWS Avg. 6

409 157 172 66

* Homes with Greywater Recycling Systems

Although the results of this comparison indicate that the GDP homes consume equal or

greater amounts of water per household relative to the REUWS average, this is not to

be construed as a shortcoming of the GDP homes and their water conservation

measures. The comparison being made here spans too broad a region, covering

municipalities from Florida to Ontario, and as far west as California and south to Texas.

Water consumption can vary drastically by region, and no mention of minimum building

code water efficiency targets, nor water prices, are outlined in the study information that

is currently available – both of which affect water consumption behaviour. It is therefore

impossible to tell whether other jurisdictions consume less water due to different

consumption patterns, efficient fixtures, or market forces.

That said, according to UN-Water, a United Nations inter-agency coordination

mechanism for all freshwater related issues, Canada consumes more water per capita

for municipal purposes than the United States. Therefore, it is expected that a Canadian

6 There was an average of 2.6 people per household in the REUWS study.


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Municipality would rank at average or higher levels of water consumption relative to its

U.S. counterparts. This fact highlights the urgent need for improved water conservation

measures to be encouraged by municipalities. With regard to the GDP, the most

important benchmark reference is the OBC to which the current housing stock has to

adhere to. It is vital to demonstrate technologies and efficiency targets which are suited

to both the local regional climate and local economic market. Overall, the GDP homes

performed well on a whole-home water consumption level.

9.3 Neighbourhood Water Consumption Benchmarking

A more accurate benchmarking comparison of the GDP homes can be achieved by

comparing the homes directly to their neighbours. This type of analysis allows for

variables such as the market pricing or water, climate, and building code minimum

requirements to be set equal amongst the neighbourhood homes and GDP homes. This

leaves water use efficiency as a leading factor of water consumption and allows the

GDP homes to showcase their water conserving features. The Region provided

Sustainable EDGE with local household water consumption data for the period

coinciding with the GDP reporting period; the same two neighbourhoods where the GDP

homes are located were used for the comparison – the total sample size was 113

homes. In both cases, the homes included in the comparison were filtered to ensure

they were built to the same OBC 2012 requirements.

The neighbourhood data provided for the comparison included outdoor use. To facilitate

a fair evaluation, a comparison was done between summer-time and winter-time water

use, the difference of which was taken to approximate outdoor water use. The rationale

being that indoor water use remains rather steady over the course of the year and any

additional consumption in the summer would represent outdoor water use. It was found

that outdoor water use represented 14% of total account use for the neighbourhood

sample. The GDP indoor water consumption values were increased by 14% to

approximate whole home consumption7.

The table below represents the culmination of this neighbourhood benchmarking

analysis for water consumption.

7 Actual metered whole home consumption for the GDP homes was not used in order to minimize the effect of data outliers which were present within the measured outdoor water consumption.


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Table 23 - Neighbourhood Water Consumption Benchmarking

Neighbourhood

Annual Water Consumption

LHD LCD

Bowmanville 482 175

Courtice 487 177

GDP Overall† 462 140 † Includes added 14% to account for outdoor water use.

The results from the benchmarking analysis indicate that the GDP homes performed

considerably better than their neighbouring counterparts when measured on a per

capita basis – a 20% reduction on a per capita basis represents a very successful

conservation effort. The LCD measurement is the most accurate method of comparison

because it accounts for the number of occupants within the home, a factor which greatly

influences household water consumption.


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10.0 Heating, Electricity, Water-Related Energy and GHG Emissions

The preponderance of modern scientific study and evidence points to climate change as

being, at least partially, induced by human activity. Chief amongst the causes of climate

change is the release of greenhouse gases (GHG) into the atmosphere through the

burning of fossil fuels and generation of energy in the form of electricity. These GHGs

trap the sun’s energy within the Earth’s atmosphere and cause increases in global

temperatures through the greenhouse gas effect.

While energy conservation measures can help a consumer’s bottom line by providing

cost savings, it is important to also note that these same conservation measures also

reduce GHG emissions – an important step in mitigating climate change. Furthermore,

water conservation is inherently tied to energy conservation, as energy is required for

moving, treating, and heating water. This interconnectedness is knows as the

water/energy nexus. Thus, every drop of water saved, saves energy, also contributing

to reduced GHG emissions.

GHG emissions vary by source, with various forms of fossil fuels emitting varying levels

of the pollutant. Electricity generation methods which involve the burning of fossil fuels

can have higher GHG emission intensities per unit of energy generated due to

inefficiencies in the generation and transmission processes. Measuring a home’s

energy end-use by the amount of each fuel source consumed allows us to quantify the

GHG emissions of the home. When energy conservation measures are implemented,

the subsequent energy savings carry with them a reduction in harmful GHG emissions

released into the atmosphere.

10.1 Greenhouse Gas Reduction from GDP Homes

The GHG reduction analysis was broken out by utility end-use. The analysis

encompassed reductions in GHG emissions at the house level due to avoidance of

energy and water consumption arising from GDP home upgrades. The analysis was

presented for energy and water utilities.

10.1.1 Grid Delivered Electricity and Natural Gas

Carbon dioxide equivalent8 (CO2e) is an internally recognized measure of greenhouse

gas emissions. Conventional building energy sources invariably have CO2e emission

8 CO2e describes carbon dioxide equivalency in reference to a mixture of greenhouse gases. It is the

amount of CO2 that would have the same global warming potential (GWP), when measured over a

specified timescale – generally 100 years. Global warming potential describes a pollutant’s efficacy in


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factors associated with their generation, use, and delivery. According to Table ‘1.2.2.1

CO2e Emission Factors’ within the Supplementary Standard SB-10 - Energy Efficiency

Supplement of the Ontario Building Code 2012, the CO2e emission factors for the

relevant building energy sources are as follows:

Table 24 - OBC 2012: CO2e Emissions Factors

CO2e Emission Factors

Building Energy Sources CO2e (kg/kWhe)

Grid Delivered Electricity (marginal based on natural gas)

0.400

Natural Gas 0.191

The homes in the GDP all have a mix of Grid Delivered Electricity and Natural Gas as

their fuel sources. Since one fuel source, electricity, has a higher GHG emission factor

than the other, tracking the breakdown of GHG emissions by fuel type will inform which

conservation measures will yield the most GHG reductions. The following table outlines

the GHG emissions per house by fuel type for the 1-year GDP monitoring period.

accelerating the greenhouse gas effect within the atmosphere – a property which varies amongst the

different gases. CO2, as the standard, has a GWP of 1, while natural gas has a GWP of 25.


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Table 25 - GDP Household GHG Emissions by Fuel Type

Home ID

Total Annual Modelled Electricity

Consumption

Total Annual Modelled Natural

Gas Consumption

Emissions from Grid Delivered Electricity

Consumption

Emissions from Natural

Gas Consumption

Total Emissions

from Building Energy

Consumption

kWh m3 kWhe kg, CO2e kg, CO2e kg, CO2e

Cod

e-B

uilt

A 11,109 2,678 28,387 4,444 5,422 9,865

B 9,862 2,079 22,037 3,945 4,209 8,154

C 9,795 2,265 24,009 3,918 4,586 8,504

D 15,379 2,481 26,299 6,152 5,023 11,175

E 15,543 2,012 21,327 6,217 4,073 10,291

F 21,781 2,454 26,012 8,712 4,968 13,681

Total 83,469 13,969 148,071 33,388 28,282 61,669

Average 13,912 2,328 24,679 5,565 4,714 10,278

As-B

uilt

A 11,012 2,323 24,624 4,405 4,703 9,108

B 9,846 1,810 19,186 3,938 3,665 7,603

C 8,142 2,076 22,006 3,257 4,203 7,460

D 14,636 2,092 22,175 5,854 4,235 10,090

E 15,330 1,707 18,094 6,132 3,456 9,588

F 19,662 2,117 22,440 7,865 4,286 12,151

Total 78,628 12,125 128,525 31,451 24,548 55,999

Average 13,105 2,021 21,421 5,242 4,091 9,333

Percent Difference of Averages 6% 13% 9%

Table 25 illustrates that GHG emission levels from electricity and natural gas

consumption were similar irrespective of house type (i.e. Code-built or As-built), with

reductions coming predominantly from the reduction in natural gas consumption.

Comparing the As-built homes to the Code-built homes shows that on average the GDP

homes reduced electricity consumption based GHG emissions by 6% and natural gas

consumption based GHG emissions by 13%. From an environmental stewardship

perspective, these results are very promising, particularly in the context of significant

growth forecasted for Clarington and Durham Region overall. In the case of the GDP

homes, space heating is provided solely through natural gas, while the plug loads are

solely electrical.

Further opportunity for GHG emissions reduction may be addressed in two ways. On

the natural gas side, with 95% efficient furnaces, there are minimal additional reductions

to be achieved by way of appliance efficiency. Instead, GHG emissions reductions can

be realized by reducing the overall amount of energy required to heat the home. This


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can be achieved through envelope upgrades which would provide greater insulation and

air tightness to the home, passive solar design, and harnessing geothermal energy,

thereby reducing the home’s energy consumption and consequent GHG emissions. On

the electricity side, appliance efficiencies are constantly improving, so choosing efficient

ones can go a long way in reducing the carbon footprint of the home. As well, installing

renewable sources of electricity generation on a home will also reduce its carbon

footprint. Furthermore, behaviour plays a large part in plug loads. Turning off lights and

appliances which are not in use will go a long way in reducing electrical energy

consumption and its associated cost and GHG emissions.

10.1.2 Water Consumption Related Greenhouse Gas Emissions

The GHG reduction analysis for water conservation was more involved due to a larger

number of contributing variables. Namely, homes in different neighbourhoods may be

supplied water from different water supply plants and the same applies for water

pollution control plants which receive water sewage from the homes. Furthermore, there

are energy intensities of supplying water and of treating sewage, and these values

further vary by facility based on the type and quantity of energy used – usually a mix of

electricity, natural gas, and diesel fuel for back-up generator operation. The energy

used to pump and treat municipal water has a carbon footprint, and this is what is

calculated within this analysis. Real data for purchased energy by the Region, the local

water and sewage utility provider, was used in order to ensure an accurate localized

approach to GHG emissions accounting. The data used was from 2014, the last year for

which full accounting was available.

The analysis method involved taking a breakdown of all fuel types purchased by each

water supply and water pollution control plant, as well as the total amount of water

pumped by each facility. The appropriate GHG emission factor was then attributed to

each fuel type to derive the amount of GHG emissions each facility produced. From this

data, the energy intensity (kWhe/ML) and GHG emission intensity (kg CO2e/ML) values

were derived. These intensities were then applied to the annual modelled water

consumption of the GDP homes in order to calculate how much GHG emissions were

avoided by the water distribution and treatment plants due to water conservation

features installed within the GDP homes. Table 26 displays the water related GHG

emissions of the GDP homes.

A detailed presentation of data is presented in Appendix L.


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Table 26 - Municipal GHG Emissions Via Water Infrastructure

Home ID

Total Modelled Annual Water Consumption

Municipal Energy Expenditure from Municipal

Water Distribution

Total GHG Emissions from Municipal Water

Consumption

L kWhe kg, CO2e

Cod

e-B

uilt

A 224,601 222 84

B 226,029 237 82

C 154,276 162 56

D 142,460 149 52

E 111,005 110 42

F 180,105 189 66

Total 1,038,476 1,069 382

Average 173,079 178 64

As-B

uilt

A 180,279 178 68

B 206,323 216 75

C 135,657 142 49

D 115,516 121 42

E 102,402 101 38

F 146,465 154 53

Total 886,642 913 326

Average 147,774 152 54

The above table illustrates the energy expended, and GHG emissions released, by the

Region as a result of providing water services to the GDP homes. Overall, the average

GDP home reduced the Region’s annual energy consumption by 26 kWhe which

corresponds to annual savings of 10 kg of CO2e per home. While these savings are not

drastic in themselves, they are a positive effect of the water conservation trend as a

whole, particularly in the context of significant growth forecasted for Clarington and

Durham Region overall.

10.1.3 GHG Reductions from House Energy and Water Reductions

Based on the comparison of Code-built and As-built emissions for the GDP homes, as

shown above in Tables 25 and 26, the total energy and water related GHG emissions

reductions and the total combined GHG emissions reductions for each house are shown

in Table 27 below.


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Table 27 – GHG Reductions from House Energy and Water Reductions

Home ID

Annual GHG Emissions Reduction -

Energy

Annual GHG Emissions Reduction -

Water

Total Annual GHG Emissions Reduction

kg, CO2e kg, CO2e kg, CO2e

A 758 17 774

B 551 7 558

C 1,044 7 1,051

D 1,085 10 1,095

E 703 3 706

F 1,530 12 1,542

Total 5,670 56 5,726

Average 945 9 954

Table 27 illustrates that on aggregate, GHG emission reductions attributed to water

conservation features in the GDP homes only accounts for 1% of total annual GHG

emissions reductions, with the remaining being attributable to energy related GHG

emissions reductions. When the focus is GHG emission reductions, the biggest benefit

is gained from energy conservation measures within the home and energy demand

reduction.


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11.0 Municipal-Level Water Consumption Reduction/Avoidance

The results of the GDP can also provide valuable insight to the Municipality and the

Region as they plan for significant growth and neighbourhood development in the area

over the next 15 years. Placing the data in the context of Clarington’s projected

population growth provides a high level demonstration of the potential implications of

water consumption patterns on municipal infrastructure development. It is important to

note that the six GDP homes do not represent a statistically significant sample size from

which to draw any conclusive results; the analysis performed in this section is for

preliminary demonstration purposes and may inform future usage projections and water

infrastructure needs assessments.

In comparison to the modelled equivalent homes built to the minimum efficiency

standards required by the OBC 2012, the average GDP home reduced its annual water

consumption by 25,3069 L. While the cost savings for the individual households were

significant, amounting to $92 in average annual savings, the savings realized by the

Region are also significant. Since the Region oversees the water pumping and sewage

treatment operations, they incur the cost of these energy and chemically intense

operations.

The analysis in this section assumes that Clarington will meet growth forecasts as

outlined by the Ministry of Municipal Affairs and Housing in its 2006 Growth Plan for the

Greater Golden Horseshoe area. Under this plan, Clarington is forecasted to reach a

population of 140,400 by 2031. In 2015, Clarington’s population is estimated at 95,220.

Clarington may require an estimated 19,400 new housing units be built between 2015

and 2031 to accommodate forecasted growth. This translates to an average annual

construction rate of 1,212 new dwellings per year. Of these new dwellings, 83% are

forecasted to be low or medium density builds, consisting of detached, semi-detached,

or townhouse homes. Therefore, for the purposes of this analysis of water consumption

reduction, it is assumed that 1,000 new dwelling units are constructed annually over the

next 15 years.

9 This value, 25,306 L, is an average which accounts for a 50% penetration rate of the greywater recycling system as a water conservation feature.


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From the results of the GDP, the average annual water avoidance breakdown is:

Greywater recycling units: 17,423 L

All other water efficiency features: 16,594 L

Total: 34,01710 L

The Region has separate costs for water supply and wastewater treatment due to the

services requiring different treatment processes; those costs are outlined as follows:

Water Supply: Total costs for the treatment and distribution transmission of drinking water per mega litre treated - $1,086.57

Wastewater: Total cost of wastewater collection/conveyance and treatment/disposal per mega litre treated - $1,039.54

The following two scenarios were considered in estimating the potential impact of

enhanced water conservation in the context of projected future growth and residential

development:

Scenario 1: Water Conservation Features, Excluding Greywater System

Under this scenario, the average home avoids 16,594 L of water consumption annually.

With 1,000 new homes coming online in the first year, the Region of Durham will avoid

supplying and treating 16.6 ML of water and realize savings of $35,300. This reduction in

water pumping and treatment will also save 16,900 kWhe of energy and avoid 6.14 metric

tons of CO2e emissions annually. These savings will compound in consecutive years.

Scenario 2: Water Conservation Features, Including Greywater Sytem

Under this scenario, the average home avoids 34,017 L of water consumption annually.

With 1,000 new homes coming online in the first year, the Region of Durham will avoid

supplying and treating 34 ML of water and realize savings of $72,300. This reduction in

water pumping and treatment will also save 34,650 kWhe of energy and avoid 12.6 metric

tons of CO2e emissions annually. These savings will compound in consecutive years.

The savings figures in this forecast are first year savings only; the savings from homes

built in sequential years would compound on top of the annual savings realized due to

the previously constructed homes.

10 This value, 34,017 L, is the sum of the average avoidance from the greywater recycling systems installed within three GDP homes (17,423 L/yr) and the average annual water avoidance due to all other water conservation features across all six GDP homes (16,594 L/yr).


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11.1 15-Year Extrapolation of Reductions

For calculating 15 year energy, water, and GHG emission reduction potential of the

GDP, three scenarios were considered:

Scenario A – Average water and energy savings observed for the GDP homes over the

projection period; this includes a 50% penetration rate for greywater recycling systems.

Scenario B – For 2016, the average energy and water savings shown by the GDP

homes are applied. For 2017 and beyond, the higher of expected energy savings due to

stricter OBC mandated efficiency measures (i.e. 15% more energy efficient than OBC

2012), or the observed GDP home average is applied. The OBC is expected to further

implement improvements in energy related efficiencies every ten years in order to allow

the industry to keep pace with new best practices; this means that in 2027 the OBC is

projected to implement an additional 15% increase in energy efficiency relative to OBC

2017. Water efficiencies are not expected to increase beyond OBC 2017; no water

efficiency improvements beyond the GDP findings are assumed. This scenario reduced

greywater recycling system penetration to a more realistic 25% of projected low and

medium density new homes.

Scenario C – For 2016, the average energy and water savings shown by the GDP

homes are applied. For 2017 and beyond use 20% above OBC 2012 for water and 25%

for energy. This savings scenario outlines the ‘aspirational’ performance target that has

been included in the green development criteria recommended to the Municipality in the

Green Development Framework and Implementation Plan (Municipality of Clarington,

December 2015). This scenario reduced greywater recycling system penetration to a

more realistic 25% of projected low and medium density new homes.

The extrapolation results are outlined in Table 28. Under the scenarios, total GHG

emissions reductions range from approximately 113,000 tonnes CO2e (Scenario A) to

299,000 tonnes CO2e (Scenario C). This serves to demonstrate the potential influence

which strengthened residential water conservation mandates may have on the GHG

mitigation planning in the context of strong forecasted residential development.


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Table 28 - 15 Year Extrapolation of Savings

En

erg

y

Water Savings Energy Savings GHG Reduction

ML MWhe Tonnes CO2e

Scenario A N/A 485,849 112,956

Scenario B N/A 657,460 173,055

Scenario C N/A 1,109,598 298,812

Water Savings Energy Savings GHG Reduction

Wa

ter

ML MWhe Tonnes CO2e

Scenario A 2,549 1,298 472

Scenario B 2,501 1,274 463

Scenario C 3,615 1,842 669


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12.0 Overall Findings, Recommendations, and Lessons Learned

A list of key findings from the GDP are summarized as follows:

1. The project is unique in that a significant measurement effort for energy and water

under actual operating conditions was undertaken for a full year for six homes.

2. Based on the measurements, the As-built homes exhibited a modelled energy

(electricity + natural gas) of use that was on average 11% less than the equivalent

modelled Code-built house. The cost savings were on average $260, ranging from

$98 to $624 per year.

3. In regards to water consumption, the As-built homes were modelled using on

average 14% or about 25,300 L less water than the Code-built average house

consumption of approximately 173,100 L per year. The average annual water

savings realized by three of the GDP homes that were equipped with a greywater

recycling system was 19,325L greater than the average of the three remaining

three GDP homes and resulted in a cost savings difference of $71 per year. The

As-built water cost savings ranged from $31 to $162 with an overall average of $92

for all six of the GDP homes.

4. On average, the energy and water use intensity for the As-built homes showed an

11% and 15% reduction, respectively, compared to the Cod-built homes. The GDP

homes equipped with greywater recycling systems were, on average, 18% less

water intensive than the comparable Code-built houses, while those GDP homes

absent of a greywater recycling system were on average 10% less water intensive

than the comparable Code-built houses. It is inferred that these results are a direct

reflection of energy and water efficiency upgrades implemented in the GDP

homes.

5. As a direct result of the greywater recycling systems, the consumption of 1311 litres

of water per person per day was avoided (on average) over the course of the

demonstration period. Modification of the greywater recycling system purge

frequency from every 48 hours to every 10 days was demonstrated to have a

substantial effect on overall efficiency (i.e. domestic water avoidance).

6. Financial assessment performed for various energy and water green practices

implemented in the homes yielded positive results. With the exception of the

11 This value is based on the whole reporting period and encompasses both the 2-day and 10-day purge cycle frequencies. Modelling all the greywater recycling systems as being 80% efficient, the average efficiency of the 10-day purge cycle setting, yields 18 litres of water avoidance per person per day.


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greywater recycling system, a positive NPV and simple payback of less than 10

years was indicated for all of the water efficiency features analyzed, including low

flow shower faucets (6.6 L/minute), low flow kitchen faucets (5.7L/min) and ultra-

low flow toilets (<3.8 L/flush). While greater water savings were realized with

greywater recycling system installed in the GDP home, improved efficiency

resulting from a longer purge frequency of every 10 days did not improve the

simple payback period below 45 years. As this emerging technology matures, it is

expected to achieve greater market penetration, which may have a positive effect

on future NPV evaluations as economies of scale take effect and drive system

prices down. With respect to energy, improvements to the building envelope and

HVAC system, as well as a higher efficiency DHW heater was deemed to be

investment worthy for the homeowner.

7. Both the HERS Index and EnerGuide energy rating systems determined “better

than code” performance for the As-built homes. Pre-occupancy rating estimated

that the As-built homes would be approximately 18% more energy efficient (on

average). Based on modelling actual post-occupancy conditions using the sub-

metering data, improved energy efficiency of 11% (on average) was found.

8. Average indoor water consumption for the GDP homes was 131 litres per person

per day. Taking into account an adjustment factor for outdoor water use, the

average water consumption for the GDP homes was estimated at 140 litres per

person per day. By comparison, the average water consumption observed

amongst a sample of 113 other households constructed in the same

neighbourhoods as the GDP homes and also subject to the requirements of OBC

2012 revealed a higher average water consumption rate of 176 litres per person

per day. The Region-wide average in 2015 was 230 litres per person per day.

9. The upgraded green practices implemented in the GDP homes also contribute to

GHG emissions reductions resulting from reduced natural gas consumption,

reduced electricity consumption, and reduced energy consumption related to water

savings (i.e. less energy used to pump, heat, and treat municipal water). The

average estimated annual GHG emissions avoided from energy and water savings

for the GDP is 955 kg CO2e. In context of future growth forecasted for Clarington,

water conservation policies have great potential to contribute to greenhouse gas

mitigation efforts.

4. Placing the data in the context of Clarington’s projected population growth provides

a high level demonstration of the potential implications of water consumption

patterns on municipal infrastructure development. Potential water supply and


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treatment savings for the Region ranged from approximately $35,000 to $72,000

annually and a reduction of an estimated 6 – 12 metric tonnes (CO2e) of GHG

emissions per year, dependent upon the uptake of greywater recycling.

Lessons may be drawn from the GDP that may inform the development of a future

Green Development Program for residential growth in Clarington:

1. It is important to keep in mind that the field of home construction will continue to

evolve over time; what is a green practice now may be normal practice in the near

future. A green development program will require regular review and updating to

remain current and to continue to drive innovation and leadership.

2. On some energy matters the OBC has been advancing aggressively (e.g. attic

insulation) and the 2017 version of the OBC would make HRV/ERVs mandatory. It

is expected that the new 2017 energy provisions would reduce the 2012 house

energy and water budgets by 15% on average. The energy and water related

green practices have made great strides in working toward this target and have

assessed the financial value of doing so. However, additional measures (and cost)

will be necessary to truly achieve 15% improved energy efficiency beyond current

OBC 2012 levels.

3. A flexible, collaborative approach was taken in determining the green practices to

be implemented for the GDP. A workshop was held to go over various green

practices that were possible, and the builders were asked what they would be

willing to implement; there was no consequence to not including a green practice.

This increased participation and resulted in a customized approach across all the

builders in terms of what practices they implemented or how. Accordingly, the

degree to which the selected measures exceeded OBC requirements varied. A

future program may consider setting performance targets for energy and water.

Performance targets generally work better than individual prescriptive measures,

and allow for more innovation through flexibility. This would allow green practices

not required by OBC to be considered as well (e.g. storm-water flow reduction by

permeable pavers, increased usage of non-potable water from rain water

collection, renewable energy supply).


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Other lessons that may be learned based on the findings of the GDP include:

1. Greywater recycling may be the last ‘low hanging fruit’ available for substantial

reductions in indoor water use. This has important implications for the OBC and

the identification of the next generation of mandated water efficiency requirements.

2. With respect to household energy consumption, the most easily controlled method

of reducing energy consumption is through passive means such as upgrades to

the envelope to reduce heat losses. Occupant behaviour is unpredictable and

challenging to influence; therefore further reductions coming from the building

design itself must be focused on. Incentivising higher performance building

envelopes, as well as passive solar design, may yield drastic additional reductions

in energy consumption that will be realized for the entire life of the home, even as

ownership of the home changes.

3. The most air tight GDP house that was constructed was also third party verified to

have the highest quality of insulation installation. Insulation installation quality, as

outlined in the RESNET National Home Energy Rating Systems Standards,

describes three levels of quality from Grade I (best) to Grade III (worst). The

additional cost of building to Grade I standards is marginal as no extra material

costs are involved. Rather, installer expertise is required to achieve this higher

standard of construction quality. It is suggested that all builders provide insulation

installation quality training to their trades’ workers in order to improve the overall

quality of the building envelope.

4. While select green practices did not demonstrate value based strictly on a financial

evaluation, the assessment did not factor in the associated environmental benefits,

including resource savings and GHG emissions reductions. Further, it does not

account for the potential risk of water and energy costs rising at a greater rate of

escalation then was assumed herein. These factors as well as other market

drivers that may positively contribute to economies of scale can greatly influence a

future re-calculation of value.


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13.0 Bibliography

Alberta Urban Municipalities Association. (2015, August 12). Updates to EnerGuide Ratings for

Homes. Retrieved from Alberta Urban Municipalities Association:

http://www.auma.ca/news/updates-energuide-rating-homes

Buchan, D. (2007). As Assessment of EnerGuide as a Requirement for New Homes.

Committee, J. F. (2015). Recommended 2016 Water and Sanitary Sewer User Rates (Report

#2015-J-59). Durham Region: The Regional Municipality of Durham. Retrieved from

https://www.durham.ca/departments/finance/water/2016WaterSewerUserRates.pdf

Durhamregion.com. (2013, 12 16). Durham water, sewer rates to rise $50. Retrieved from

Durhamregion.com: http://www.durhamregion.com/news-story/4267642-durham-water-

sewer-rates-to-rise-50/

Dziegielewski, B. (2014). End-Use Based Benchmarking of Residential Water Use. WaterSmart

Innovations (p. 14). Las Vegas: WRF 4309 - Residential End Use Study Update REUWS2.

OEE, NRCan. (2012). Residential Sector Table 2: Secondary Energy Use and GHG Emissions by

End-Use. Retrieved from Natural Resources Canada:

http://oee.nrcan.gc.ca/corporate/statistics/neud/dpa/showTable.cfm?type=CP&sector=res&ju

ris=on&rn=2&page=0#footnotes

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Appendices available by request. To obtain a copy, email: [email protected]

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