making the case for green

The Green Roundtable(copyright © Green Roundtable 2007)

The Green Roundtable

Making the Case for Green-Basic economics

and


Green Roundtable

Consulting, education, trainingand strategic planning

to create healthy environments byintegrating principles of

sustainability into mainstreamplanning, design and construction.


Objectives

- What are the key value-added propositions in greenbuilding? – i.e. selling green

- What are the basic economics of green building?

- How can we financially justify green?

- How can we sweeten the pot for our clients?

Answer the following questions:

- Why do green?


4

Why do green….


5

Some sad realities….

• Ozone depletion

• Air & water pollution

• Destruction of worlds forests & green spaces

• Species & biodiversity loss

• Acid rain

• Collapse of world’s fisheries

• Fresh water scarcity

• Topsoil loss; Soil contamination

Even if you don’t believe that the global warmingthreat is real, we are facing these certain realities:


6

And if global warming is real…

• Crop failure on a massive scale

• Increases in drought frequency

• Deadly heat waves

• Rising sea levels/ coastal flooding

• Increased frequency & duration of storm activity

• Expansion of desert areas

• Increases in disease vectors


7

On a more local or personal level…

• Rapidly rising energy costs

• Escalating prices on consumer goods

• Blackouts/ brownouts

• Water shortages

• Supply chain interruptions

• More frequent economic losses due to increased

storm intensity & flooding


8

The United States produces 25% of globalgreenhouse gas emissions. Americans

produce twice as much per person than otherindustrialized nations

Some sobering facts…


9

Water tables are now falling in countries thatcontain over half the world’s people



There are currently 1,243 EPA Superfundsites on the National Priorities List and 60

more proposed (as of 3/20/07)



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The incidence of asthma has increaseddramatically over the last 25 years in the U.S.

and other industrialized nations.



12

The EPA estimates that indoor air can be upto five times as contaminated with VOCs as

outside air.



The EPA also reports that the airbornecontaminants found in our homes are threetimes more likely to cause cancer than the

pollutants outside



14

Cancer clusters have been identified insome more-affluent communities and have

been attributed to chemically-intensivelandscape management practices



A 15-year study in Oregon concluded thatwomen who work in the home have a 54%higher death rate from cancer than women

who work outside the home



16

China recently caught up to the United Statesin terms of overall energy consumption.

India isn’t far behind.

The U.S. & Canada are still the per capitaleaders by far



17


The U.S., with 5% of the worlds population,consumes more than a third of it’s resourcesand over a quarter of its energy resources.


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Half of U.S. greenhouse gas emissions come frombuildings (construction/ operation)

Buildings account for nearly half of the total energyuse in the United States

Buildings represent the single largest energyconsumer in the U.S., followed by the transportation

sector

Where do buildings fit in…


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Additional housing sector facts…

According to HUD, if Americans can reducehome energy use by 10% over the next ten

years (a doable number!), it will be theenergy equivalent of 40 new power plants

(600 Mw) and the greenhouse gas equivalentof 25 million vehicles


Additional housing sector facts…

There are more than 76 million residentialbuildings in the USA today

Estimates of residential energy consumptionas a proportion of the nation’s total energyload range from around 20 – 40%

From 2000 to 2005, winter heating costs fornatural gas increased by 115%, oil by 135%,and electricity by 18%


22

Food for thought….


23


24

Perhaps the most sobering fact of all…

It has been estimated that in order for the currentpopulation of the Earth to live at the same quality of life asthe industrialized nations, it would require the resources of

four ‘Earth equivalents’.


25

This we know…

As a nation, the United States uses a disproportionateshare of the world’s natural resources

We live on a planet of finite natural resources

We are currently using those resources at anunsustainable rate


26

This we know…

These conclusions are rooted in simple physics,chemistry, biology and economics

Energy prices are likely to trend in only one directionfor the foreseeable future! Most other resource pricesare likely to follow the same trend


27

A solution:Green Building


Why build green?

• Reduces the ecological footprint of the building

• Creates a safer and healthier indoor environment

• May improve property resale value

• Saves on utility expenses

• May increase affordability

• Typically results in a more durable, maintenance-free building

• Reduces our dependence on foreign oil

Building green:

• Provides security/ passive survivability


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• Economics- Reducing energy cost/ protecting thebottom line

• Health- Maintaining a safe and healthy environmentfor one’s family & oneself

• Personal impact- Addressing the greater good-minimizing environmental footprint

The three prime movers (in order):


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• The cool factor

• The “shiny metal objects” mentality

• Peer pressure

Some other motivators:


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Defining green building:

The effective and responsible integrationof the built environment into the naturalworld to protect natural resources andensure healthy and comfortable indoor

environments


What makes it green?

• Low embodied energy (entire lifecycle)

• Minimizes impact on wildlife habitat, green space,waterways, etc

• Minimizes depletion of natural resources

• Poses minimal harm to humans during itsmanufacture, transport, installation, end-use ordisposal


The quantity of energy required to manufacture, andsupply to the point of use including:

• Extraction• Transportation• Manufacturing

• Assembly• Installation• Some definitions also include:

Disassembly & Removal

What is embodied energy?


Water Efficiency

Sustainable Sites

Energy & Atmosphere

Materials & Resources

Indoor Environmental Quality

Innovation & Design Process

The LEED Credit Categories


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Cornerstones of green building (structure itself)

Site Site

Site Site


How green is it?

• The “no-build” option is always the greenest way

• Smaller is greener

• More efficient material resources use is better

• The more durable (in use) & maintenance free thebetter


Selection criteria: Materials

• Efficiently uses energy & resources

• Contains high recycled material content

• Derived from rapidly renewable resources

• Can be reused/ recycled at the end of it’s useful life

• Can be down-cycled at the end of it’s useful life

• Biodegradable


Post-Consumer vs. Pre-Consumeraka Post-Industrial

Recycled Content


Defining green: Design resources

• Building America-http://www.eere.energy.gov/buildings/building_america/about.html

• Environmental Building News/ Greenspec-http://www.buildinggreen.com)

•http://www.austinenergy.com/Energy%20Efficiency/Programs/Green%20Building/Sourcebook/index.htm


Measuring Green:Rating Systems

• LEED - www.usgbc.org

• Energy Star Homes- www.energystar.gov

• International Energy Conservation Code (IEEC)-http://www.iccsafe.org/

• HERS (http://www.energy.ca.gov/HERS)


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• Incorporate energy efficient design details

• Create a high-performance building envelope

• Employ water conservation strategies

• Employ natural daylighting techniques

• Use energy-efficient lighting, equipment & appliances

General strategies:

• Create comfortable & healthy indoor environments

• Minimize impact on building sites/ area


Economics of green building


Economic realities

Up front costs or first-costs of green buildingare often greater than conventional building

That doesn’t need to be the case!


Additional construction costs


Additional Pitfalls

• Uninformed & resistant code and municipal officials

• Products that ‘go away’

• Sourcing materials

• “Greening” small-scale projects


Keys to success

• Careful design

• Using a team approach between owners,design professionals and code officials, andbringing everybody together early in theprocess

• Early planning


Architects

BuildingOwners

Planners

Federal,Local,and StateGovernments

UtilityManagers

NonprofitLeaders

Engineers

BuildingTenants

PropertyManagers

ProductManufacturers

InteriorDesigners

CodeOfficials

LandscapeArchitects

FinancialPlanners


• Start planning and design as early as possible

• Adopt a systems approach during the designphase- understand that virtually all systems/components affect the others

• Determine ‘lead time’ on products as early aspossible- this may allow some flexibility in shipping,will minimize project delays, etc.

• Design carefully and then finalize your design asearly in the process as possible- change orders canbe expensive!

• Make sure that you understand the properties ofthe materials and how to use them! Do yourhomework

Managing up-front costs (& expectations!)


Managing up-front costs, continued

• Right-size systems- Don’t use rule of thumbapproaches

• Use a trade-off approach- offset increased cost inone product or system through savings in another

• Go green by incorporating no-cost design featuresand elements– The Low-hanging Fruit

• Offset increased first cost with rebates & incentives

• Match the project scale to the genuine space needs ofthe client!


Underlying all:

ScaleScaleScale


The average size of a U.S. single-familyhouse has increased by 33% since 1975. At

the same time average family size hasdecreased.

Consider this:


• Take advantage of marginal cost of installing higherquality materials- e.g. adding thicker insulation(reduces life-cycle cost, but maybe not up front cost)

Managing up-front costs, continued


Justifying increased up-front costs

Making the case for reduced Life-Cycle Cost or TotalCost of Ownership (TCO):

• Green buildings usually use less energy to operatethan their conventional counterparts

• Green buildings are typically more durable &maintenance-free due to the application of soundprinciples of building science

• There are typically additional benefits that help towarrant the increased cost


The trump card

A University of Michigan study demonstrated thatgreater than 90% of the embodied energy in a home

is attributable to operating energy

Reduce operating energy and potentially reduceTCO significantly


Low-hanging Fruit(A sampling)


Using the site

• Take advantage of existing vegetation if possible-deciduous trees for shading; coniferous trees aswind breaks

• Site structure on south-facing slope for maximumsolar gain; take advantage of wind & solar resources

• Use natural terrain features to protect structure fromcold winter winds

• Site structure downwind from lakes, ponds, wetlandsfor natural cooling

• Take advantage of hills that funnel breezes

• Use earth-berming if topography permits


Building orientation/ layout

• Orient structure along East-West axis; i.e. long sidefacing south

• Minimize glazing area on north, northeast & west-facing walls

• Maximize glazing on south-facing walls tomaximize winter solar gains

• Incorporate buffer spaces in structure- closets alongoutside walls, vestibules, enclosed porches, etc.

• Minimize surface area-to-volume ratio; avoidcomplicated designs w/ many intersecting planes


Sustainable sites: Low-hanging fruit

• Minimize heat urban island effect by using light-colored pavement

• Use landscape features that allow stormwater topercolate into soil- e.g. bioswales

• Manage stormwater by using pervious paving

• Use water conserving landscape maintenancepractices– Xeriscaping, native plantings, etc.

• In general, minimize site disturbance


Common name Botanical Name HeightAmur Maple Acer ginnala 20'-25'

Austrian Pine Pinus nigra 50'

Japanese Black Pine Pinus thunbergii 6-10'

Cornelian Cherry Cornus Mas 20-25'

London Plane Platanus x acerifolia 50'

White Oak Quercus alba 50'

Low-water trees:


Common name Botanical Name HeightBroom Cytisus scoparius 5-6'

Flowering Quince Chaenomeles specoisa 6'-10'

Junipers Juniperus sp. 2'-9'

Cinquefoil Potentilla 3'-4'

Butterfly Bush Buddleia davidii 6-10'

Rose-of-Sharon Hibiscus syriacus Diana 6-8'

Winterberry Ilex verticillata 8-10'

Mugo Pine(dwarf) Pinus mugo 3-4'

Low-water shrubs:


Common name Botanical Name HeightBearberry Arctostaphylos uva-ursi 6-8"

Creeping Lilly-turf Liriope spicata 6-8"

Violets Viola sp.. 6-8"

Snow-in-Summer Cerastium tomentosum 6-8"

Low-water groundcovers:


Common name Botanical Name HeightNew England Aster Aster Novae-angliae 15-30"

CommonBlanketflower Gaillardia aristata 24-36"

Moonbeam Coreopsis verticillata 24-36"

Purple Coneflower Echinacea purpurea 24-36"

Low-water perennials:


Materials: Low-hanging fruit

• Employ advanced framing techniques

• Keep it small!

• Use structure as finish

• Use salvaged/ surplus materials

• Use low-VOC paints, sealants & adhesives


Design strategies: Advanced Framing

• Saves on labor cost since fewer “sticks” installed

• Saves on framing lumber expense

• Reduces lumber disposal cost/ impact

• Savings estimates range to 20% of overall framingexpense

• Improves thermal envelope of building– moreplaces to insulate!

• Can offset the cost of using FSC-certified lumber


Advanced framing & efficiency

• Provides more room for insulation!

• Reduces bridging heat loss


Advanced Framing

• “Right-sized” headers; insulated, engineered headers

• Features 2 x 6 studs on 24” centers

• Jack studs eliminated at window openings

• No headers in non-load bearing partitions

• Single top plate if trusses/ roof rafters placeddirectly over wall studs

• Open corner framing (2-stud corners)

• Ladders at T-intersections


Durability: Low-hanging fruit

• Minimize roof penetrations

• Maintain proper grading & ground clearances

• Incorporate overhanging roofs

• Keep vegetation away from structure

• Use well-designed wall sections


Energy: Low-hanging fruit

• Right-size systems

• Use structured plumbing & PEX piping

• Move ductwork into conditioned space

• Spec Energy Star

• Use zone lighting

• Use natural daylighting strategies

• Use zoned heating


Cooling

Use ceiling fans w/ cathedral or high ceilings toeliminate temperature stratification (both heating andcooling season)

Shade air conditioner and heat pump condensers w/vegetation or artificial shading (be careful w/ deciduousvegetation) if you have to locate on sunny side

Locate AC/ heat pump condensers on N or NE orNW side out of direct sun!


Cooling

Use deciduous vegetation on south, SW and westsides of structure for summer shading; use vines ontrellises too

Use coniferous (evergreen) trees/ shrubs to redirectbreezes/ wind

Install awnings, overhangs and other shadingstructures, such as pergolas

Make sure attic space is well vented


Take advantage of prevailing winds for natural cooling

Maximize cross-ventilation

Use building elements to funnel winds (e.g. casementwindows)

Use light-colored shingles or roof membrane on very lowpitched or flat roofs

Cooling


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A sampling of strategies &approaches for reducing life-

cycle cost or TCO


Green Practice:Water conservation


Order a free water saving kit at:www.mwra.com/04water/html/watsense.htm

MWRAA water conservation resource


Water conservation

• Use low-flow showerheads & faucet aerators

• Collect rainwater in rain barrels for landscapeirrigation

• Incorporate graywater systems

• Use demand pumps in supply system

• Use dual-flush or composting toilets; waterlessurinals


83


The Portland Group- Splash Showroom244 Needham St.Newton, MA 02164617.332.6662

Coroma Dual-Flush Toilet Source

See: http://www.caromausa.com/products/toilets.htm


Green Systems:Gray water


Gray water

• Collected from drain-waste-vent system other thantoilets & kitchen sinks with garbage diposals (“Blackwater”)

• May be difficult to get local code approval

• Generally used for flushing toilets, landscapeirrigation & other non-potable, utility purposes


http://www.gaiam.com/product/eco-home-outdoor/energy-efficient-climate-control/energy-saving-tools/toilet+lid+sink.do

Gray water: A direct approach


Rainwater collection

• For 1000 sq ft roof area, 15 – 25,000 gallons ofrainwater can be collected annually in Eastern states

• Using rainwater helps to maintain aquifers and publicwater supplies at adequate levels

• Combined with drip-irrigation systems, collectedrainwater can keep landscaping vibrant even duringdrought conditions

• Rainwater does not contain minerals, so it ispotentially better for use as laundry/ wash water

• Rainwater does not contain chlorine so it is better forplants, garden ponds, etc.

• Rainwater is free, and inexpensive to collect & store!


http://www.cleanairgardening.com/33galrainbar.html


Xeriscaping (low-water-landscaping)

• Two major aspects:-Making maximum use of available precipitation-Selecting species with low water requirements

• Use drip irrigation & soaker hoses

• Use mulches

• Create water retention landscape features

• Group plants

• Use native plantings, they are better suited to naturalrainfall patterns

• Use plantings to create windbreaks & shade toprotect from drying winds and sun


Drip emitters


Soaker Hose


Energy ConservingDesign Strategies (a sampling)


Design Strategies: Thermal mass

Thermal mass:

• Can be used to store heat in winter

• Can help to moderate temperatures year-round

• Key element in passive solar design


Thermal mass: How to incorporate

• Masonry veneers on exterior walls

• Masonry finishes on interior walls & floors

• Fireplaces, chimneys & interior masonry features

• Thickened walls- e.g.double drywall layer

• Green roofs

• Cob & masonry construction

• Water features/ elements


Thermal mass: additional benefits

• Acoustic comfort

• Increased structural integrity in some situations


Design Strategies: Green roofs

• Properly designed, can pay for themselves in 10 –15 years via reduced energy cost

• Especially effective in reducing cooling costs

• By some estimates, can reduce cooling costs by upto 30% in single-story structures


Green roofs: additional benefits

• Can provide stormwater management

• Reduce urban heat islands

• Help to minimize global warming

• May extend the life of your roof

• Provides green space & wildlife habitat

• Improves acoustic comfort


Design Strategies: Passive solar


Passive solar

Basic requirements:

• Collect it…

• Retain it…

• Store it…

• Distribute it…

Free heat from the sun; ‘greenhouse effect’ (goodkind!); good southern exposure/ solar aperture needed


5 Major elements ofPassive Solar

• Aperture/ Collector (glazing)

• Absorber

• Distribution

• Thermal storage (mass)

• Control


Requirements

• Glazing area to collect sunlight- 7% rule- So.-facing

• Window insulating system (and good buildingenvelope insulation) to keep heat in at night

• Thermal mass- needed to store heat if net windowarea is more than 7% of total floor area

• Shading—vegetation (deciduous), or shadingstructures like awnings, roof overhangs andpergolas, to prevent overheating during warmer mos.


Requirements,cont.

• Distribution system—to remove excess heat toother parts of house where it may be needed inwinter

• Ventilation system—to remove excess heat tooutside during warm weather


Passive Solar Rules-of-Thumb

• Orientation of aperture area should be within 30degrees of true south

• Aperture should ideally be shade-free from 9am –3pm

• Direct gain systems are most common and easiestto integrate into most designs; glazing should notexceed 12% of building floor area

• South-facing glass should be vertical and shouldhave some kind of overhanging to shade fromsummer sun

• Thermal mass can help to moderate temperature insummer as well as store heat in winter


Passive Solar Rules-of-Thumb

• Skylights should be avoided on all but north andnortheast-facing roof surfaces, as they can otherwisecontribute to overheating in the summer, and won’tprovide appreciable gains in the winter due to lowangle of sun

• Deciduous trees can provide good summershading, but should not be located too close tohouse/ sunspace, as trunk/ branches may providetoo much shade in winter

• In sunspaces, may need powered ventilation tominimize summer overheating

• Well designed passive solar can provide 5 –25% ofspace heating needs with no added cost


Angled glass may not be the best configuration,especially without an overhang!


Skylights may contribute to summer overheatingand winter heat loss.


Frost-protected Shallow Foundations

• Improves thermal performance

• Reduce excavating expense

• Reduce site impact

• Reduce material expense

• Note: Local code officials may be resistant toapproving this foundation system


Design Strategies: Natural daylighting

• Can reduce lighting loads and cooling loads

• Residential systems typically consist of skylights,clerestory windows or tubular daylighting devices(TDD’s; “sun tubes” or “light tubes”)

• Improves indoor environmental quality


Design Strategies: Natural daylighting

• Skylights in south, southwest and west-facing roofscan contribute to summer overheating

• Skylights in more north-facing roof surfaces cancontribute more light on cloudy days

• TDDs may contribute less to overheating


Sky tube (TDD)


Natural daylighting

• Light-colored walls reflect light deeper into structure

• Light shelves can serve the same purpose, andaccomplish this w/o excessive glare; they provideshading as well

• Combine daylighting strategies with photo-resistorcontrolled lights to avoid excessive lighting duringdaytime

• Wide windowsills/ shelves can reflect light as well,but may contribute to glare

• Landscape features can be utilized for reflectinglight into interior as well (paved surfaces, waterfeatures, etc)


Light shelves shade windowwhile providing natural daylightvia light reflected from topsurface

Can help light to penetratedeeper into structure


Suggested Room SurfaceReflectances:Ceilings: > 80%Walls: 50%-70%Floors: 20%-40%Furnishings: 25%-45%


RADIANCE is a lighting anddaylighting visualization tooldeveloped by LBNL and is availableover the web:http://radsite.lbl.gov/radiance/

Lighting & Daylighting Analysis


Green Practice:Improving the Building Envelope


Building envelope, definition

All of the elements of a building that separate andisolate the outdoor environment from the indoorenvironment. This may include walls and wall finishes,roofs and roof finishes, doors, windows, skylights andbasement floors and walls.


Key Principle- Saving home energy

As a general rule, for the average home/homeowner, the greatest energy savings will beachieved through managing the demand side of

the equation, rather than the supply side.

In other words, you’ll get better bang for your buckthrough energy conservation measures, like insulating

& minimizing air infiltration, than incorporatingexpensive renewable energy systems such as wind

and solar.


An exception:

Exceptions to this may include passive solar, andsituations where you qualify for a substantial rebateand/or credit for other renewable energy systems(keep in mind the embodied energy of systemsthough!)

There are other compelling reasons to performupgrades like this, such as reduced reliance onforeign energy resources, promotion of renewableenergy & local industry, passive survivability, etc.


Preventing heat loss

• Air seal (prevent infiltration)

• Best bang for buck through air sealing! Begin here!

• Insulate

• Use landscape features- vegetative shields, etc.

• Address lifestyle issues


Building envelope, functions

• Protect structural elements and interior of structurefrom weather, esp. moisture

• Help to maintain proper thermal regime withinstructure

• Help to maintain proper humidity regime withinstructure

• Prevent infiltration of outside air and contaminants

• Acoustically isolate interior of structure from outsidenoise

• In essence, act as ‘membrane’ for the structure


Building envelope failure

• External water leaks leading to:-Damaged structural elements-Damaged interior finishes-Insulation failure-Damaged interior furnishings and appliances-Mold problems

• Air leaks leading to:-Infiltration of unconditioned air/ Drafts-Direct escape of conditioned air to outside-Infiltration of outdoor contaminants

• Excessive accumulation of interior moisture in wallcavities causing structural/ insulation failure & mold

• Excessive heat transfer from inside to outside


Building envelope components

• Exterior finish- wood siding, vinyl siding, brick, etc.

• Weather membrane/ air barrier/ drainage plane-building paper, Tyvek, Typar, etc.

• Exterior sheathing- usually plywood or OSB

• Wall/ ceiling cavities (inc. structural members &insulation)

• Vapor retarders/ barriers

• Interior wall finish

• Doors & windows


Codes and standards

• Sixth edition of MA building code was officiallysuperseded by 7th edition as of January 1st, 2008

• New MA energy code based on 2006 InternationalEnergy Conservation Code; more stringent

• Better to follow Energy Star Homes or HERSguidelines for maximum energy efficiency and codecompliance (see resources slide)


Minimizing air infiltration(sealing building envelope)

• Min .35 Air changes per hour (ACH) for goodventilation; max .50 for energy efficiency (EnergyStar)

• Openings to attic spaces are some of worst offenders

• Seal obvious openings- pipe penetrations, atticscuttles, electrical receptacles, recessed lights, etc.

• Any place where two building planes meet is goodcandidate for air sealing

• For additions/ new construction, use exterior airbarrier to minimize infiltration


Housewrap tominimize airinfiltration &protect frommoisture


Blower doortest tomeasure airleakage


Air leakage pathways


Air leakage proportion through various pathways


Attic hatches/ scuttles are a major leakage pathway


A commercial solution for attic openings

See also www.efi.org


Insulate header/ rim joists w/ rigid foam & expanding foam


Seal joints between intersecting planes w/ expanding foam


Fireplaces are usually NOT an effective heating appliance!They lead to excessive heat loss via drafts up chimney.


Air sealing, online productsources

• efi.org

• conservationtechnology.com


Insulating

• Resistance to heat flow (insulating ability) measuredin R-value; not important to know how this is derived;mainly need to know that it’s a relative scale ofeffectiveness, and the higher the R value, the betterthe insulating value

• Code represents absolute minimum; newer codehas more stringent requirements; tied to window area;R-49 ceiling, R-21 walls, R-30 floors, R-13 basementtypical


Insulating guidelines

• Remember that if you use A/C you are minimizingcooling expense by buttoning up your house as wellas heating expense

• Go for low-hanging fruit- e.g. add more atticinsulation first if it is accessible and is not wellinsulated; Don’t forget the basement!

• Look for additional opportunities to insulate (otherthan typical wall/ ceiling cavity insulation)

• Try to eliminate bridging (perimeter) heat lossthrough structural elements, as it greatly reducesoverall insulation effectiveness


Basement/ foundation insulation often overlooked


Bridging heat loss

• Eliminate with:-Double wall construction (very expensive!)-Foam skin-Cross-banding attic batt insulation

• Conductive heat loss through structural members


Bridging heat loss- snow melts over roof rafters


Bridging heat loss caused wall-staining over structural members


Bridgingheatloss throughsill plates


Layer of foamminimizes bridgingloss through sill;top of concretefoundation wallwill also receivelayer of foam


Thermograph to check heat loss through walls (insulation effectiveness)


Windows

• ‘Low-e’ coating reflects heat back into structure

• Performance measured in “U-value”; inverse of R-value; measure of material’s ability to conduct heat;the lower the U-value, the better

• Double-glazed, argon filled preferred; Diminishingreturns with triple glazing

• Typical heat loss through windows about 20%

• Look for U-value of .35 or less

• Always look for Energy Star & NFRC labels(energystar.gov; nfrc.org)


NFRC Label


Windows

• Provide nighttime insulation

• Used ‘tuned” glazing strategies

• Incorporate/ install overhangs & other shadingdevices where appropriate

• E.g., Use windows w/ low SHGC on west-facingwindows; high SHGC on south-facing


Cellular insulating window shades can provide nighttime insulation


Side tracks make them easier to operateand reduce air leakage around edges


Green Practice:HVAC/ Plumbing


HVAC & Plumbing Systems

• “Right-size” systems using analysis tools (Manual J)rather than rule-of-thumb methods; a right-sizedsystem can be up to 40% smaller than aconventionally-sized system

• Use demand pumps in DHW supply system(gothotwater.com)

• Use heat recovery devices on DWV pipes(gfxtechnology.com)

• Use instantaneous hot water heaters (tankless)


Tankless water heaters

• Examples of brands: Rinnai, Noritz, Takagi

• Gas-fired typically more responsive and can provideneeded capacity more effectively

• Cost more than standard water heaters but last longer

• More choices as to location/ placement

• Direct-venting; e.g. can exhaust through wall

• Save energy by eliminating standing heat loss (vs.conventional tank-style water heater); estimated savings24 – 34%

• Look for min. flow rates of 0.3 – 0.5 gal./min.


High-efficiency heating

• Boilers tend to have higher AFUE than furnaces

• Make sure heating systems have Annual FuelUtilization Efficiency (AFUE) of at least 83% for oil-fired and 90% for gas-fired, and Seasonal EnergyEfficiency Rating (SEER) of at least 13 for coolingsystems

• Closed-cycle, condensing-type boilers and furnacesare more efficient; they extract additional heat fromwarm flue gases

• These systems often don’t need conventional flue pipe,they can side vent, but they require a dedicatedcombustion air source (coaxial flue pipe)


Ductwork

• Seal ducts; use duct mastic for this if possible,otherwise make sure duct tape is UL listed

• Insulate ducts in unconditioned spaces; for cooling(A/C) ductwork, make sure insulation has externalvapor barrier to minimize condensation

• When insulating ducts in unconditioned basement,you may make basement too cold; insulatebasement walls instead


Lighting

• Use solar landscape lights

• Use motion sensor outdoor lights

• Put timer switches on bathroom fans

• Use dimmer switches & occupancy sensors

• Spec CFL’s & fluorescents


Appliances

• Buy Energy Star!

• Specify horizontal axis washing machines

• Specify dishwashers w/ booster heater

• Don’t specify oversized AC equipment!


http://www.energystar.gov/index.cfm?c=dishwash.pr_dishwashershttp://www.energystar.gov/index.cfm?c=clotheswash.pr_clothes_washershttp://www.energystar.gov/index.cfm?c=boilers.pr_boilers

Energy Star savings calculators


A general list of tools offered by the U.S. Departmentof Energy are available over the web at:http://www.eere.energy.gov/buildings/tools_directory/subjects.cfm/pagename=subjects/pagename_menu=whole_building_analysis/pagename_submenu=load_calculation

General analysis tools


Sweetening the pot


Rebates and incentives

• Energy efficient mortgages

• MA state renewable energy tax credit

• Mass Technology Collaborative’s CommonwealthSolar Initiative

• MA state sales tax exemption

• Federal Energy Policy Act of 2005

• See DSIRE database (Database of StateIncentives for Renewables & Efficiency):http://www.dsireusa.org/

• Utility incentives


Federal Energy Policy Act of 2005

Examples:

• Energy Star windows/ skylights: 10% of cost up to$200 for all windows

• Exterior/ Storm doors: 10% of cost up to $500

• Insulation: 10% up to $500

• Geothermal heat pump: $300

• http://www.energy.gov/taxbreaks.htm


Energy Efficient Mortgages

• Remodelers/ Refinancers:-Owner gets all the EEM benefits without moving.-Make improvements which will actually save

money.-Increase the potential resale value .

• Allows you to increase your debt-to-income ratio

• Home Energy Rating System (HERS) report mustindicate that home will save money as a result of theimprovements- http://www.energy.ca.gov/HERS/;http://www.energyratings.org/

• For more info:http://www.pueblo.gsa.gov/cic_text/housing/energy_mort/energy-mortgage.htm


MA Renewables Tax Credit

• Solar Water Heat, Solar Space Heat, Photovoltaics,Wind

• 15% of cost up to $1000

• Excess credit may be carried forward three years

• http://www.state.ma.us/doer/programs/renew/renew.htm#taxcred

• Personal tax credit


MA State Sales Tax Exemption

• 100% of sales tax exempt; no maximum

• Solar Water Heat, Solar Space Heat, Photovoltaics,Wind, Geothermal Heat Pumps

• http://www.state.ma.us/doer/programs/renew/renew.htm#taxcred


MTC Small Renewables Initiative

• Rebates up to $50,000

• PV, wind, microhydro

• See http://www.masstech.org


MTC Commonwealth Solar

• $68 M Funding

•http://www.masstech.org/renewableenergy/commonwealth_solar/index.html


•High-efficiency space heating equipment

•High-efficiency indirect water heating equipment

•ENERGY STAR® qualified windows

•ENERGY STAR® qualified thermostats

•ENERGY STAR® qualified central air conditioning

•ENERGY STAR® air source heat pump systems

Typical utility rebates


GRT: www.greenroundtable.orgBuilding Green: www.buildinggreen.comEnergy Star: www.energystar.govCharles River Watershed: www.crwa.orgUS Green Building Council: www.usgbc.orgRenewable Energy: www.nrel.govUS DOE: www.eere.energy.gov/buildings/EPA: www.epa.gov/ne/greenbuildings

Residential Green Building Guide:A Web Source Book for New Englandwww.epa.gov/ne/greenbuildings

NAHB: Model Green Home Building Guidelines:www.nahb.org

Resources


• Upcoming workshops• Reference library• Samples library• Cyber Lounge• Online resources at nexusboston.com (in the

pipeline)• Local green building community

And don’t forget about NEXUS!


Local Resources


The Green Roundtable, Inc. (GRT) is an independent non-profitorganization whose mission is to mainstream green building andsustainable design and become obsolete. We work toward this goal bypromoting and supporting healthy and environmentally integrated buildingprojects through strategic outreach, education, policy advocacy andtechnical assistance.

[email protected]

617-374-3740

www.nexusboston.com38 Chauncy Street, Boston

Located in downtown Boston, NEXUSwelcomes all to come ask questions,research topics, and attend tours andevents on green building and sustainabledesign innovation.

THANK YOU

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