bnwat06 water use in new and existing buildings

Version: 1.0

First created: 11/03/2011 Updated: http://efficient-products.defra.gov.uk Last reviewed: 11/03/2011 1 of 20 0845 600 8951

BNWAT06: Domestic water use in new and existing buildings Supplementary briefing note

Version 1.0

This Briefing Note and referenced information is a public consultation document and will be used to inform Government decisions. The information and analysis forms part of the Evidence Base created by Defra’s Market Transformation Programme.

1 Introduction

This briefing note summarises how water is used in new and existing households and non-

households. This note does not examine in detail product-specific issues. These are

addressed in separate briefing notes that are referred to in this document.

1.1 Purpose of the briefing note

The purpose of this Briefing Note is to:

Define domestic water use, in household and non-household buildings;

Present an overview of the total volume of water put into supply per day in England

and Wales to understand the relative importance of household demand;

Present a framework for estimating domestic consumption in non-households;

Examine/quantify the relative importance of households’ outdoor use (i.e. this does not

include external use in non-households).

Version: 1.0


1.2 Content of the briefing note

This briefing note contains the following information:

Section Information

1: Introduction

2: Key facts Water put into supply, definitions of building types

3:Domestic water use

in households

Existing households, new households, external use, impact of behaviour

4: Domestic water

use in non-

households

Existing non-households, new non-households

2 Key facts

2.1 Water put into supply

The following facts and statistics are for England and Wales only (2009/10).

Total water supplied per day: 14,449 Ml/d1

Approximately half of this was supplied to households: 7,599 Ml/d2;

Approximately a quarter of this was supplied to non-households: 2,857 Ml/d;

Just under a quarter (3,280Ml/d) leaked from the distribution system3; and

The remaining small amounts are used operationally, provided unbilled, taken illegally

or supplied to customers requiring untreated water.

Water companies report annually how much water they supply to metered and un-metered

households and non-households. However, it is not possible to determine from this reported

data how much of the water supplied to non-households is for domestic use, as opposed to

commercial or process use. However, the data shows that, in 2009/10, 72 per cent of the

high quality potable water put into supply was for household and non-household demand.

1 Water UK Water Supply and Infrastructure Data http://www.water.org.uk/home/resources-and-

links/waterfacts/waterindustry/data 2 Sum of data in June Returns 2010 http://www.ofwat.gov.uk/regulating/junereturn/jrlatestdata/

3 Ofwat (2010). Service and delivery – performance of the water companies in England and Wales

2009-10. http://www.ofwat.gov.uk/regulating/reporting/rpt_los_2009-10.pdf

Version: 1.0


2.2 Building definitions

Table 1 defines the types of buildings and water use considered within the scope of this

Briefing Note.

Table 1.1 Types of water use and building types

Element Definition

Households Properties used as single domestic dwellings (normally occupied), receiving water for domestic purposes which are not factories, offices or commercial premises

4.

This does not include residential non-household properties such as prisons, hospitals, student halls, boarding schools etc.

Metered households

Households who pay for their water services based on their consumption, as measured by a water meter.

Un-metered households

Households who pay for their water services based on a charge related to the rateable value of the property or estimated consumption. The latter includes households that have requested a meter but cannot have one installed for technical reasons.

Non-households Properties receiving water for domestic purposes but which are not occupied as domestic premises, or where domestic dwellings are combined with other properties, or where properties are in multiple occupation but only have one standing charge

4.

Domestic-type use

Water uses such as toilet and urinal flushing, basin taps, kitchen taps (excluding commercial catering facilities), showering, bathing, domestic clothes and dishwashing, basic cleaning. This type of water use occurs in both household and non-household situations. It includes domestic supplies to factories, offices and commercial premises

4.

Domestic outdoor use

Any potable water that is consumed outside of households after being drawn from the mains distribution system. This can include personal garden watering, car washing, window cleaning etc. External use of rainwater or greywater is not included because this does not require any further water to be drawn from the distribution system.

Process use This includes industrial processes, launderettes, commercial car washers, industrial cleaning/cooling etc, large scale landscape watering (golf courses etc).

Ml/d Megalitres per day (1Ml/d = 1,000,000 litres, 1,000m3)

4Ofwat (2007) June return reporting requirements and definitions manual 2011

Version: 1.0


3 Domestic water use in households

3.1.1 Existing households

Domestic water use can be broken down into its constituent parts, commonly referred to as

the micro-components of water use. The components of household water use are shown in

Figure 3.1, along with average use quantities. This shows that the greatest use of water in

households is for toilet flushing (around 26 per cent). Water use associated with personal

hygiene including showering and bathing accounts for 19 per cent and 12 per cent

respectively. Water used in washbasins, for clothes and dishwashing and for outdoor use

each account for between 5 and 10 per cent of daily household water use.

Figure 3.1 Average micro-component water use in existing households*

Toilet f lushing, 26%

Bath use, 14%

Show er use, 19%

Hand basin, 9%

Clothes w ashing,

10%

Dish w ashing, 7%

Garden use, 8%

Miscellaneous use,

6%

Car w ashing, 1%

*Water use in an average existing household. Based on water company submissions data5.

Although the data presented in Figure 3.1 are for an average existing household, it is

important to recognise that actual water use can vary considerably. The amount of water

used for each micro-component is determined by three parameters:

Ownership

5Data based on customer surveys, not 2004 MTP documents. Results are very similar to the micro

component data provided by the majority of water companies.

Version: 1.0


All homes will have at least one toilet, washbasin and kitchen sink. However, homes may or

may not have a bath, shower, washing machine, dishwasher or outdoor tap.

Frequency of use

How often water consuming appliances, fixtures and fittings are used determines water use.

For example, some people may choose to shower more than once a day.

Volume per use

The volume of water used by a fixture or fitting each time it is used may vary. For example,

modern toilets are required to have a flush volume not exceeding 6 litres per flush. The flush

volumes of older cisterns are typically 7 to 9 litres but can be even greater.

All three of the above parameters are affected by user behaviour. Householders may select

products based on their performance, for example power showers. Such choices will

increase the volume per use.

3.2 New households

The population of England and Wales is forecast to increase from 55,260,000 in 2010, to

63.0 million in 2030, an increase of 9.15 million6. Housing data from the Department for

Communities and Local Government (CLG) shows that the number of households in

England and Wales has increased from 17,025,000 in 1971 to 23,992,500 in 2010. Housing

levels are forecast to continue increasing in response to the increasing population and the

increasing number of low occupancy/single person households. DCLG data suggests that

by 2030 the number of households in England and Wales could reach 29,168,600.

6 http://www.statistics.gov.uk/pdfdir/pproj1009.pdf

Version: 1.0


Figure 3.2 Housing and population forecast (England and Wales)

Forecast housing and population growth

20,000,000

21,000,000

22,000,000

23,000,000

24,000,000

25,000,000

26,000,000

27,000,000

28,000,000

29,000,000

30,000,000

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

50,000,000

52,000,000

54,000,000

56,000,000

58,000,000

60,000,000

62,000,000

64,000,000

Households in England and Wales Population

Improvements in the water efficiency of new homes are being driven by statutory

requirements such as Part G of the Building Regulations, which requires that “the estimated

consumption of wholesome water of a new dwelling should not be more than 125 litres per

head per day (l/h/d)”7, including a fixed allowance of 5 l/h/d for outdoor use. The non-

statutory Code for Sustainable Homes (CSH) has introduced three performance standards

for water efficiency:

Code Level 1 and 2 (120 l/h/d)



Local planning authorities can stipulate the performance standards for new developments

using tools such as the Code for Sustainable Homes to drive improvements in the efficiency

of new homes. The Building Regulations state that water use for a new home should be

estimated using the Water Efficiency Calculator for New Dwellings8. The same calculator is

used to estimate water use of homes complying with the Code for Sustainable Homes. The

calculator is shown in Table 3.1.

7 HM Government (2010). The Building Regulations 2000. Part G: Sanitation, hot water safety and

water efficiency. 2010 Edition. 8 Communities and Local Government (2009) The water efficiency calculator for new dwellings.

Version: 1.0


Table 3.1 The water calculator for new dwellings

Installation type Unit of measure Capacity/flo

w rate

(1)

Use Factor

(2)

Fixed use

(l/h/d)

(3)

Water use (l/h/d)

(4) = [(1)x(2)]+(3)

WC (single flush) Flush volume (litres) 4.42 0.00

WC (dual flush) Full flush volume (litres)

1.46 0.00

Part flush volume (litres)

2.96 0.00

WC (multiple fittings)

Average effective flushing volume (litres)

4.42 0.00

Taps (excluding kitchen/utility room taps)

Flow rate (litres/minute)

1.58 1.58

Bath (where shower also present)

Capacity to overflow (litres)

0.11

Shower (where bath also present)


0.11 0.00

Bath only Capacity to overflow (litres)

0.50 0.00

Shower only Flow rate (litres/minute)

5.60 0.00

Kitchen/utility room sink taps


0.44 10.36

Washing machine Litres/kg dry load 2.1 0.00

Dishwasher Litres/place setting 3.6 0.00

Waste disposal unit Litres/use If present = 1

If absent = 0 3.08 0.00

Water Softener Litres/person/day 1.00 0.00

(5) Total calculated use (l/h/d)

(6) Contribution from greywater (l/h/d)

(7) Contribution from rainwater (l/h/d)

(8) Normalisation factor 0.91

(9)

Total water consumption (for

comparison with CSH)

= [ (5) – (6) – (7) ] x (8)

(l/h/d)

(10) External water use 5.00

(11)

Total water consumption (for

comparison with Building Regulations

standard)

= [ (9) + (10)

(l/h/d)

Version: 1.0


Figure 3.3 shows the estimated micro-component use for a new household built to comply

with the water efficiency standard set out in the Part G of the Building Regulations. This can

be compared to Figure 3.1 that shows average micro-component values from water

company data. The comparison shows that average demand per person in a new build

home is approximately 14 litres less than in existing homes (note, the data supporting Figure

3.1 includes homes built in recent years that also have some element of water efficiency built

in). The reduction in water use is driven by improvements to the efficiency of WCs. This

results in showering becoming the dominant water use within the home (increasing to

around 33 per cent of water use). As WC flush volumes are further reduced and much more

efficient washing machines and dishwashers are installed, personal washing (showering and

bathing) will become increasingly dominant. The interplay between showering and bathing

(ownership and frequency) will influence consumption patterns and the direction that the

market takes in terms of shower type (efficient versus power shower) will be critical.

Figure 3.3 Daily micro-component water use in new households (CSH level 3)*

Toilet f lushing,

14.7%

Bath use, 16.6%

Show er use,

31.0%

Hand basin, 5.5%

Clothes w ashing,

10.4%

Dish w ashing,

2.6%

Garden use, 9.4%

Miscellaneous use,

9.8%

Car w ashing, 0.0%

*as estimated by the water calculator for new dwellings

It is important to recognise that the proportion of domestic water use attributed to each

micro-component by the water efficiency calculator is dependant on the volume of use of

each fixture and fitting. Component trade-offs are possible: for example, more efficient taps

may help to offset the demand of a shower with a greater flow rate. It is also important to

recognise that the use factors presented in Table 4.1 represent an estimate of average water

use. They do not account for the possible ranges of human behaviour.

Improvements to the performance of water consuming fixtures and fittings will contribute to

new homes becoming more water efficient. This will primarily be through reductions in the

volume of use of individual fixtures and fittings. Previous studies have highlighted that user

acceptability is key to successful improvements in water efficiency. For example,

Version: 1.0


showerheads with lower flow rates must be perceived by the householder as offering a

similar or improved showering experience.

3.3 External water use (households)

External water use in households refers to any potable water that is consumed outside of the

domestic dwelling after being drawn from the mains distribution system. External use may

be sourced from an internal tap (e.g. the kitchen cold tap) but generally an external tap is

used. External taps are outside of the MTP remit. However, this section highlights the main

issues of external use that are relevant.

External water use depends on season, peak days9, socio-economic group10 and time of

day. The proportion and total volume of domestic water consumption that is used externally

is heavily influenced by these factors. The influence of seasonal and climatic factors upon

external water use means that there is a likelihood of high external water demand occurring

during periods of drought. Reducing the quantity of water consumed externally could help to

reduce the impact of drought and decrease the normal level of domestic water consumption.

Outdoor use activities:

Garden watering. Hoses can use upwards of 540 litres of water per hour depending

on the pressure and hose size. Sprinklers typically use 540 to 1000 litres per hour (9

to 16 litres per minute). Watering cans come in a variety of volumes, typically between

7 and 13 litres11.

Vehicle washing.

Filling and/or topping-up of ponds and water features. Pre-formed ponds vary in

volume, with typical examples ranging from 150 to 4500 litres12.

Pressure washers (for outdoor cleaning). Pressure washers connect to a water

source, such as an external tap, and deliver the water from a nozzle at high pressure.

This high pressure increases the cleaning power of the washer and therefore reduces

the time taken to perform the cleaning task.

Recreational water use (swimming pools, hot tubs, paddling pools).

The British Swimming Pool Federation (BSPF) states that the average volume of an in-

ground pool is around 75,000 litres13. This is a significant quantity of water in the household

setting. Once filled, swimming pools lose water through evaporation, splashing and

9 a day when the maximum temperature equals or exceeds 18°C and the daily rainfall is less than

2mm on the day and the two previous days 10

ACORN classification system 11

B&Q www.diy.com Accessed 12 Jan 2011 12

www.worldofwater.com Accessed 12 Jan 2011 13

BSPF response to Defra’s Consultation on proposed changes to powers to restrict non-essential uses of water

http://www.diy.com/

http://www.worldofwater.com/

Version: 1.0


backwashing of filters. Pools do not need refilling (except when repairs are necessary) but

do require regular topping-up.

The BSPF claims that an average sized covered pool consumes an average of 66 litres of

water per day. This is based upon a 30 litres loss through evaporation and a fortnightly

backwashing of the filter using 500 litres (averaged over the fortnight to about 36 litres per

day).

BSPF states in the same response that an average hot tub has a volume of 1,500 litres and

needs completely refilling every three months. This is an equivalent usage of about 16 litres

per day. These figures reflect averages and hot tub volumes can range from 400 to 2,500

litres14. Manufacturers recommend that hot tub filters should be cleaned every two to four

weeks. This is performed using a garden hose or tap and will add to the water consumption

attributable to hot tubs15.

3.4 Impact of behaviour on water consumption

Behaviour is a major factor affecting how much water people use. Whilst products can be

restricted in terms of the volume of water they use, individual’s behaviour, particularly

frequency and duration of use, is much more variable. As well as frequency of use,

behaviour also includes the choices that people make such as choosing to take a short or a

long shower, or choosing to water the garden with a watering can, hose or sprinkler.

Behaviour is influenced by external factors. For example showering and outdoor water use

increases during periods of hot weather. There is a lot of uncertainty around the behavioural

aspects of water use and about how climate change will affect water using behaviour.

Whilst water using behaviour cannot be controlled, it can be influenced. One of the barriers

to water efficiency in England and Wales is the perception held by many people that, unless

there is a drought, there is no problem. In 2009 Defra commissioned research16 to uncover

the wide range of factors that influence people’s water using habits: their underlying

assumptions, beliefs and aspirations, and water use expectations. The report concluded

that people need to be engaged in order to modify their behaviour. They need to witness

examples and be actively encouraged. Finally, they need to be enabled; they need to know

what they can actually do and how to do it.

An additional factor that can influence behaviour is domestic water metering. In England

and Wales, 37 per cent of households currently are charged on the basis of their metered

consumption17. Charging for water use in this way is widely acknowledged to influence

water use, particularly discretional uses such as garden watering. As a result, the total

14

MTP hot tubs scoping study (unpublished) 15

www.splashspas.co.uk. Accessed 12 Jan 2011 16

Defra (2009). Public Understanding of Sustainable Water Use in the Home

A research report completed for the Department for Environment, Food and Rural Affairs by Synovate. http://randd.defra.gov.uk/Document.aspx?Document=EV0503_8291_FRP.pdf

17 Data from Ofwat website. http://www.ofwat.gov.uk/regulating/reporting/rpt_tar_2010-

11hhwatcust.xls. Accessed 11-01-11

http://www.splashspas.co.uk/

http://www.ofwat.gov.uk/regulating/reporting/rpt_tar_2010-

Version: 1.0


volume of water used in a metered household is generally around 10 per cent lower than un-

metered household water use18.

18

Defra (2008). Future Water: The Governments Water Strategy for England.

Version: 1.0


4 Domestic water use in non-households

4.1 Water use in existing non-households

Less research has been undertaken on domestic-type water use in non domestic buildings,

compared to that completed for households. A literature review completed for the

Department for Communities and Local Government19 found that although there is a

considerable body of information in the public domain concerning water consumption in non-

household buildings, there is very little information specifically on the domestic-type uses of

water. The same study found that there is also a lack of published information on the

frequency of water consuming activities (e.g. number of toilet flushes per person per day) in

non-household building types.

A 2006 CIRIA report, Water key performance indicators and benchmarks for offices and

hotels20, set benchmarks for water use per bedspace (hotels) or employee (offices) per

annum and per day. However, this report did not disaggregate water use into micro-

components.

Unlike in households, it is much more difficult to identify and quantify generic micro-

components of domestic use in non-households. This is because of the wide range of non-

household building types and the ways in which they are used21.

Framework methodology

This section sets out a framework methodology to estimate non-household domestic

demand in England and Wales. This is based on the MTP method proposed in 2007.

Identify building types

The first step is to identify the relevant building types and the types of domestic water use

activity within them. Information on property types is available within the British Standard BS

6465 Sanitary installations. Code of practice for the design of sanitary facilities and scales of

provision of sanitary and associated appliances.

Table 4.1 lists examples of non-household building types used to estimate domestic water

use22.

19

Entec (2009) Research to Assess the Costs and Benefits of Improvements to the Water Efficiency of New Non-household Buildings. Research report completed for the Department of Communities and Local Government, currently unpublished.

20 http://www.ciria.org/service/Web_Site/AM/ContentManagerNet/ContentDisplay.aspx?Section=Web_Site&ContentID=8988

21 Entec (2009) Research to Assess the Costs and Benefits of Improvements to the Water Efficiency of New Non-household Buildings. Research report completed for the Department of Communities and Local Government, currently unpublished.

22 MTP (2006) BNWAT22: Domestic water consumption in domestic and non-domestic properties Version 1.1

Version: 1.0


In general, non-household buildings are:

Used for commercial, industrial or institutional purposes;

Often occupied on a transient basis; and

Generally not used for residential purposes (although there are some clear exceptions

to this such as university halls of residence, prisons and nursing homes).

Domestic-type uses are defined in Table 1.1. Water consumption from commercial fittings

(e.g. commercial dishwashers, washing machines, glass washing machines, etc.) is not

included in domestic use calculations. A key difference between domestic water use in

households and non-households is the additional water used for urinal flushing.

Table 4.1 Categories and sub-categories on non-household building types

Category Sub category

Accommodation for elderly, Sheltered accommodation

NHS psychiatric; NHS other; Local Authority children’s home; Local Authority other; housing association sheltered accommodation; other children’s homes.

Residential and nursing homes Nursing homes; other residential care homes; other establishments; medical and care establishments; other establishments.

Staff in offices, shops, factories and other non domestic premises

Manufacturing; electricity, gas and water supply;

wholesale and retail trades, repairs; hotels and restaurants; transport; storage and communications.

Financial intermediation Real estate, renting and business activities; public administration and defence; social security; education; health and social work; other.

Facilities in shops and shopping malls

-

Schools Special schools; primary schools; secondary schools; nursery schools; boarding schools; other schools.

Buildings used for public entertainment

Cinemas; theatres; town halls; libraries; leisure centres (excluding swimming pools).

Hotels Hotels; guest-houses; farmhouses; bed and breakfast accommodation; flats/apartments; self catering; hostels; universities/schools; self-catering holiday camps; catered holiday camps; camping; caravans.

Version: 1.0


Restaurants, cafés, canteens and fast food outlets

-

Pubs and licensed bars -

Swimming pools

Estimate population

The next step is to estimate the population (workers, visitors, residents etc) in the non-

households that will be using the facilities. Table 4.2 lists key sources of information for

estimating occupancy in different types of non-households.

Detailed water consumption and water efficiency analyses may also require information on

the number of products installed. For example, the most efficient flush mechanism for a

suite of urinals is dependent on the intensity of use; a waterless or 1.5 litre push button flush

may be more efficient where there are a small number of infrequently used urinals; whereas

a timer-based system may be more efficient to auto-flush urinals which are used more

frequently. BS 6465 sets out the legal (minimum) requirements for sanitary provision (i.e.

the number of WCs, urinals, washbasins) relevant to the number of people expected to

occupy the building.

Table 4.2 Sources of population data by property type

Property type Sub-type Population data source

Accommodation for elderly,

sheltered accommodation.

Residential and nursing homes

All www.statistics.gov.uk Table KS23

Population 'all communal establishment residents'

Staff in offices, shops, factories

and other non domestic

premises.

All www.statistics.gov.uk Table S039

Occupation by industry

Facilities in shops and

shopping malls.

All www.brc.org.uk British Retail Consortium

Schools. All www.education.gov.uk

Buildings used for public

entertainment.

Cinemas

Theatres & libraries

Town halls

Leisure centres

www.esrc.ac.uk

www.statistics.gov.uk

www.statistics.gov.uk and www.prospects.ac.uk

www.prospects.ac.uk

Hotels. All www.tourismtrade.org.uk/marketintelligenceresearch

Restaurants, cafés, canteens

and fast food outlets

All Kearney, J., et al (2001). Eating patterns -temporal

distribution, converging and diverging foods, meals

http://www.statistics.gov.uk/


http://www.brc.org.uk/

http://www.esrc.ac.uk/



http://www.prospects.ac.uk/

Version: 1.0


eaten inside and outside of the home – implications

for developing FBGD. Public Health and Nutrition:

4(2B) 693-698.

Pubs and licensed bars All www.statistics.gov.uk

Kearney, J., et al (2001). Commercial and Industrial

Floorspace and Rateable Value Statistics 2005

(2005 Revaluation).

Swimming pools All www.nationalwatersafety.org.uk

Estimate ownership and frequency of use

The next step is to estimate ownership and frequency of use in non-households. Table 4.3

sets out a range of assumptions that may be applied by analysts. These are based on

assumptions within the 2007 MTP briefing note BNWAT22: Domestic water consumption in

domestic and non domestic properties. Further work is needed to review and update these

assumptions.

The 2007 MTP briefing note BNWAT22 presented a method where property SIC codes were

applied to SIC code consumption data taken from a report produced in 1999. There has

been no up to date research on water consumption per SIC code since this report and this is

a major gap in information.

The REWARD report23 presented the water consumption for various industrial and

commercial sectors by SIC code. The 2007 MTP note matched the SIC codes from

REWARD and the property types in BS 6465 as closely as possible to produce the following

list of industries for which domestic consumption was estimated using the assumptions in

Table 4.3. The results are presented in Table 4.4.

Food and drink industry (SIC code 15);

Retail industry (SIC code 52);

Hotels (SIC code 55);

Education (SIC code 80);

Health and social work (SIC code 85);

Recreation, culture and sport (SIC code 92);

Public administration and defence (SIC code 75); and

All other (all other SIC codes).

23

Cambridge Econometrics/Environment Agency (2004). REWARD (Regional and Welsh Appraisal of Resource Productivity and Development) Key Industrial Environmental Pressures - Water Use


Version: 1.0


Table 4.3 Assumptions on ownership and frequency of use

Property type WC Urinal Basin/bath use Shower Other

Accommodation for the elderly, sheltered

accommodation.

As per household

use.

n/a As per household

use.

As per household use.

Residential and nursing homes.

As per household

use + 2 uses

n/a As per household

use.

As per household use. 4 litres/day drinking.

Staff in offices, shops, factories etc. Male to

female 1:1. 220 working days. Average office

size is 66 persons*

Female = 4 x WC

Male = 1 x WC, 3 x urinal

Timed flush (1.5l x 30mins)

4 x 0.5 litres per person per day

Facilities in shops and shopping malls.

Only shops with an area of over 1,000 m2 are

required to provide toilets. The majority of

facilities are covered by the 2,150 major outlets.

1 visit to WC/urinal

per visit.

1 WC use:6 urinal uses.

Schools. Male to female 1:1

195 schools days (day pupils).

252 school days (boarders).

3 uses per day of facilities. (7 uses for

boarding pupils).

2 WC use:1 urinal uses

Zero bathing for day pupils (no data).

One bathing event per day for boarders (0.25 x

bath: 0.75 shower). Average 42 litres per use.

2 litres/day drinking (day pupil)

4 litres/day (boarder).

Buildings used for public entertainment.

Male to female 1:1

1 visit to WC/urinal per visit.

Libraries: 1 use per 100 visitors

1WC use:6 urinal uses

Version: 1.0


Hotels. 2 persons/room. Hotels are all ensuite.

B&Bs, hostels, university accommodation have

shared facilities

4 WC uses per

person per night

n/a One bathing event per night. Washbasin tap

used as per households.

Kitchen tap use in B&B is half of household use.

Self catering. 2 persons As per household

use.

n/a Normal use Normal use No domestic kitchen tap.

Half household washing

machine use.

Restaurants, cafés, canteens and fast food

outlets. Male to female 1:1. 57 meals per

person per year

1 use per visit 1 WC use:6 urinal uses No data on domestic tap use in

cafes. Many premises have

domestic taps behind the bar.

public house/bar 2 uses per visit 1 WC use:6 urinal uses

Swimming pools

Male to female 1:1

1 use per visit 1 WC use:5 urinal uses 8 litre/min. 2 uses per

visit: 30 second pre-swim.

60 second post swim.

* www.communities.gov.uk

http://www.communities.gov.uk/

Version: 1.0


Table 4.4 Measured and estimated domestic consumption in non-household

buildings

Source: MTP (2007) BNWAT22: Domestic water consumption in domestic and non domestic

properties.

4.2 Water use in new non-households

Part G of the Building Regulations does not include a water consumption performance

standard for new non-households . However, improvements in the water efficiency of new

non-household buildings are being driven through assessment against sustainability

measures such as the Building Research Establishment Environmental Assessment

Methodology (BREEAM).

BREEAM is a package of assessment methods and tools designed to help construction

professionals understand and mitigate the environmental impacts of the developments they

design and build. It comprises a set of assessment criteria that include both quantitative and

qualitative assessments and a credit scoring system that is then used to define the buildings

BREEAM standard. BREEAM Buildings can be used to assess the environmental

performance of any type of building (new and existing).

BREEAM has produced construction standards for a wide range of specific commercial and

domestic buildings including:

Courts;

Ecohomes (new homes, apartments/flats, and houses);

Multi residential;

Healthcare buildings;

Version: 1.0


Industrial buildings (storage & distribution, light industrial units, factories and

workshops);

Offices;

Retails;

Education;

Prisons; and

Other buildings (including leisure complexes, laboratories, community buildings and

hotels).

Through BREEAM, credits are awarded for water performance as part of the overall

assessment of the building. Local planning authorities and organisations and businesses

can request builders and developers to build new non-household buildings to meet specific

BREEAM performance standards.

A simple fittings based water efficiency standard has been published by AECB24. This

standard can be equally applied to households and non-households, old and new.

Transforming the market towards more water efficient products will reduce demand within

new non-household buildings. Many of the product types that can be installed to address

domestic water use in the home will also be appropriate for use in certain non-household

buildings. For example, basin taps and showerheads that are used in the home are also

appropriate for use in hotels. Conversely, there are water consuming products that are only

suitable for application in non-household situations. These include urinals (which are very

uncommon in households), and types of tap aimed to rigorously prevent water from being

wasted during hand washing (e.g. automatic or percussion taps). The performance

achievable from these fixtures and fittings is discussed in more detail in the product-specific

briefing notes.

Within the non-household setting, users may be willing to accept different levels of

performance from water fittings to what they expect at home. For example, people who use

showers at work are likely to do so as a result of cycling or running to work, or through

activities undertaken during work hours. In these circumstances, showers with lower flow

rates may be more acceptable as the shower is used for personal hygiene rather than for the

showering ‘experience’ that might be expected in the home.

24

http://www.aecb.net/standards_and_guidance.php

Version: 1.0


Related MTP information

BNWAT07: Water and energy use

Changes from earlier versions

This briefing note replaces the following previous briefing notes:

BNWAT22: Domestic water consumption in domestic and non domestic

properties

BNWAT28: Water consumption in new and existing homes

BNWAT27: Domestic external water use – an overview

Consultation and further information

Readers are encouraged to review this document and provide suggestions that may

improve the quality of information provided. Email [email protected] quoting the

document reference, or call the MTP enquiry line on +44 (0) 845 600 8951.

For further information on related issues visit http://efficient-products.defra.gov.uk

http://www.mtprog.com/PolicyBriefs/Stage1.aspx?intPolicyBriefID=500021&strPolicyBriefTitle=UK%20Water%20Consumption%20of%20Domestic%20Showers&intPolicyBriefSector=6

bnwat06 water use in new and existing buildings

Documents