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The Building (Guernsey) Regulations, 2012
The Development and Planning Authority’s calculation methodology for assessing water efficiency in newdwellings in support of Regulation 23
The Water Efficiency Calculator (Guernsey) for new dwellings
Development &Planning Authority
2012
edi
tion
With
May
201
6 am
endm
ents
MAIN CHANGES MADE BY THE MAY 2016 AMENDMENTS
1. Text changes made to reflect the new structure of government post May 1st 2016. All references to Departments have been removed.
How this Water Efficiency Calculator (Guernsey) differs from the UK version1. Ingeneraltherearedifferentlegislative
referencesreflectingGuernseylegislation.
3. The UK Building (Approved Inspectors, etc.) Regulations2010arenotinforceinGuernsey.Thereforeapprovedinspectorsare not recognised on the Island and all references have been removed.
3. There are no references to the UK’s Code for Sustainable Homes requirements.
4. This document assumes that the Water EfficiencyCalculatorsoftwarewillbeusedfor the assessment process.
WaterEfficiencyCalculator(Guernsey) Regulation23
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PAGE
Introduction 4
The Requirement 4
Section 1 - General Guidance 5 Rainwater harvesting and greywater re-use 7 Swimming pools and Jacuzzis 7
Section 2 - Using the calculator software 8
Table 1 9
Alternative approach 9
Example printout for submission 10
Contents
WaterEfficiencyCalculator(Guernsey)Regulation23
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Regulation 23
The Requirement
Extract from the Building (Guernsey) Regulations 2012
WATER EFFICIENCY
Waterefficiencyofnewdwellings. 23. (1) Thepotentialconsumptionofwholesomewaterbypersonsoccupyingadwelling,to
whichthisregulationapplies,mustnotexceed125litresperpersonperdaycalculatedinaccordancewiththemethodologysetoutintheWaterEfficiencyCalculatorforNewDwellings,asrevisedfromtimetotime,publishedbytheDepartment.
(2) Thisregulationappliestoadwellingwhichis–
(a) erected, or
(b) formed by a material change of use of a building within the meaning of regulation7(a)or(b).
Introduction
Thefollowingdocumentsetsoutthewatercalculationmethodologyforassessingthewholehousepotablewaterconsumptioninnewdwellings.ThecalculationmethodistobeusedtoassesscomplianceagainstthewaterperformancetargetsinBuilding(Guernsey)Regulations2012,regulation23 as set out below. It is not a design tool for water supply and drainage systems. It is also not capable of calculatingtheactualpotablewaterconsumptionofanewdwelling.Behaviourandchangingbehaviourcanalsohaveaneffectontheamountofpotablewaterusedthroughoutahome.
WaterEfficiencyCalculator(Guernsey) Regulation23
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Regulation 23
1.1Thisdocumentmustbeusedinconjunctionwiththe‘Excel’spreadsheet‘WaterUseCalculator’available to download from www.gov.gg/planning.AllconsumptionfiguresbelowmustbeinputtedintothiscalculatorandthesummarysheetprintedtobesubmittedaspartofthefullplanssubmissiontoBuildingControlforconsiderationundertheBuildingRegulations
1.2Thecalculationmethodrequirestheuseofwaterconsumptionfiguresprovidedfrommanufacturersproductdetails.Beforetheassessmentcanbecarriedout,figureswillneedtobecollectedfrommanufacturersproductinformationtodeterminetheconsumptionofeachterminalfitting,including:
a. WCsi.FlushingcapacityfortheWCsuiteincludingconsumptionatfullandpartflushfordualflushWCs.
ii.WheremultipleWCsarespecifiedwithvariousflushingcapacities,eachflushingvolumemustbeincluded separately.
b. Bidetsi.BidetsareexcludedfromtheWaterEfficiencyCalculatorfornewdwellingsduetotheirminimal
waterconsumption,andalthoughthereisinsufficientresearchtoquantifythisconsumption,anecdotalevidenceshowsthatthereisevidencethatbidetsoftendisplaceotherwaterconsumptionratherthanincreaseconsumption.
c. Tapsi.Flowrateofeachtap,atfullflowrateinlitresperminutemeasuredatadynamicpressureof
3±0.2 bar (0.3±0.02 MPa) for high pressure (Type 1) taps, or at a dynamic pressure of 0.1±0.02 bar(0.01±0.002MPa)forlowpressure(Type2)taps(BSEN200:2008,sanitarytapware,singletapsandcombinationtapsforsupplysystemsoftype1and2.Generaltechnicalspecifications)includinganyreductionsachievedwithflowrestrictions.
ii.Wheremultipletapsaretobeprovided(e.g.separatehotandcoldtaps)theflowrateofeachtapwillbeneededinordertocalculateanaverageflowrate.
iii.For‘clicktaps’andothertapswitha‘waterbreak’,themanufacturer’sstatedfullflowrateshouldbeusedtoperformcalculations(measuredasdescribedabove).Donotusetheflowrateatthebreakpoint.Afactorforpercentageofflowrateisalreadyassumedwithintheusefactorfortaps.Thereiscurrentlynoresearchtoprovideaseparateusefactorfor‘clicktaps’soastandardusefactor is applied.
iv.Tapsonbathsshouldnotbeincludedinthecalculationasthewaterconsumptionfrombathtapsistakenaccountofintheusefactorforbaths.
d. Bathsi.Totalcapacityofthebathtooverflow,inlitres(excludingdisplacement,thisisalreadyincludedin
the use factor for baths).
ii.Wheremultiplebathsarespecifiedwithvariouscapacities,eachindividualbathmustinincludedseparately.
iii.Jacuzzisarenotincludedinthewaterefficiencycalculatorastheyaregenerallynotfilledonadailybasisandtheirwaterconsumptionoverayearisminimal.
Section 1 - General Guidance
WaterEfficiencyCalculator(Guernsey)Regulation23
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Regulation 23
e. Dishwashersi.LitresperplacesettingderivedfromthefiguresquotedontheEUEnergyLabel.
ii.Wherenodishwasheristobeprovidedandthereforeconsumptionfiguresareunknown,afigureof1.25litresperplacesettingmustbeassumed.
iii.Wheremultipledishwashersarespecifiedwithvariousconsumptions,eachappliancemustbeincluded separately.
f. Washing machinesi.LitresperkilogramofdryloadderivedfromthefigurequotedontheEUEnergyLabel.
ii.Wherenowashingmachineistobeprovidedandthereforeconsumptionfiguresareunknown,afigureof8.17litresperkilogrammustbeassumed.
iii.Wheremultiplewashingmachinesarespecifiedwithvariousconsumptions,eachappliancemustbe included separately.
g. Showersi.Flowrateofeachshowerattheoutletusingcoldwater(T≤30˚C),inlitresperminutemeasured
at a dynamic pressure of 3±0.2 bar (0.3±0.02 MPa) for high pressure (Type 1) supply systems, or at a dynamic pressure of 0.1±0.05 bar (0.01±0.005 MPa) for low pressure (Type 2) supply systems (BSEN1112:2008,Sanitarytapware.Showeroutletsforsanitarytapwareforwatersupplysystemstype1and2.Generaltechnicalspecifications).
ii.Wheremultipleshowersarespecifiedwithvariousflowrates,eachappliancemustbeincludedseparately.
h. Water softeners (where present)i.Percentageoftotalcapacityusedperregenerationcycle.
ii.Waterconsumedperregenerationcycle(litres).
iii.Averagenumberofregenerationcyclesperday.
iv.Numberofoccupants(basedontwooccupantsinthefirstbedroomandoneoccupantperadditionalbedroomassuming2occupantsinstudioflats).
v.Watersoftenersthatdonothaveawaterconsumptionsuchaselectromagnetictypes,arenotincludedinthecalculation.
i. Waste disposal units (where present)i.Wherepresent,astandardconsumptionof3.08litresperpersonperdaymustbeassumed.
j. External taps
i.FlowratesofexternaltapsarenotincludedinthecalculationasafixedallowanceoffivelitresperpersonperdayisassumedforexternalwateruseinRegulation23.
GENERAL GUIDANCE
WaterEfficiencyCalculator(Guernsey) Regulation23
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Regulation 23GENERAL GUIDANCE
Rainwater harvesting and Greywater re-use1.3Insomecasesrainandgreywaterrecyclingmaybeusedasameansofreducingwaterconsumption
toachievehigherwaterefficiencyperformancelevels.Thismaybeneededwhereoptionsforimprovingtheefficiencyofterminalfittings(taps,WCsetc.)hasbeenmaximisedandfurthersavingsarestillneeded.Rainwaterharvestingmayalsobeusedasameansofreducingsurfacewaterrunoff.Thedetailsrequiredtodeterminethesavingsthatcanbemadeusingthesesystemsareasfollows:
a. Greywateri.Manufacturerorsystemdesignerdetailsonthepercentageofusedwatertoberecycled,taking
into account the storage capacity of the system.
ii. The volume of recycled water collected from waste bath, shower and washhand basin, dishwasher and washing machine usage.
iii.TheconsumptionoffittingswheregreywateristobeusedinaccordancewhichcanincludeWCsand washing machines.
b. Rainwater (in accordance with BS8515)i.Collectionarea
ii.Yieldco-efficientandhydraulicfilterefficiency
iii. Rainfall (average mm/year)
iv. Daily non-potable water demand
Swimming Pools and Jacuzzis
1.4LargewaterconsuminginstallationssuchasswimmingpoolsandjacuzziswherethewaterisreplacedoveragreatertimeintervaldonotneedtobeincludedaspartofthewatercalculationsforRegulation23.
WaterEfficiencyCalculator(Guernsey)Regulation23
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Regulation 23
Section 2 - Using the calculator software
2.1 ThefollowinguserguidanceistoaidwiththeuseoftheWaterUseCalculatorsoftwareavailabletodownload from www.gov.gg/planning
2.2 Flow rate from taps (excluding bath and bidet taps) at a standard three bar dynamic pressure (0.3MPa) ( l/min)
2.3 Flow rates from showers at a standard three bar dynamic pressure (0.3MPa) at temperature of 37 C (l/min)
2.4CapacityofBaths(litres)(Note-asthecalculationworksonbathcapacity,thereisnoneedtoincludebathtapsinthe“Taps-excludingkitchentaps”sectionofthecalculator)
2.5 Flushing Volumes for Dual and Single Flush WCs (litres)
2.6WateruseperplacesettingforDishwashers(litres)
2.7WateruseperkgofdryloadforWashingMachines(litres)
2.8WhetheraWasteDisposalunitisattachedtothesink(litres)
2.9Theamountofwateroverthestandard4%allowanceusedperregenerationcycleifinstalled(litres)
2.10Thecapacityofanygreyorrainwaterharvestingsysteminstalled(litres)
2.11 Thisinformationshouldbeavailablefromthesuppliersoftheseproductsandatableisprovidedbelowwhichprovidesguidanceoftheaverageflowratesandcapacities
2.12Thecalculationallowstheuseofgreyorrainwatertoreducemainswaterdemand
2.13FurtherinformationisavailableinGuernseyTechnicalStandardGoftheBuildingRegulations.
Oncompletionofthespreadsheetsoftware,thatindicatesapositiveassessmentresult,thecalculationsheetmust be printed and included as part of the full plans submission to Building Control when applying for a building licenseundertheBuildingRegulations.
WaterEfficiencyCalculator(Guernsey) Regulation23
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Regulation 23USING THE CALCULATION SOFTWARE
Table 1 showssomesamplevaluesbasedoninformationfromwww.waterwise.org .uk actual values must be obtainedfromtheindividualappliancestobeusedforthefitoutstageoftheconstruction.
Component Typical Range of Consumption Consumption Taps Basin 6 l/min 2 - 20 l/min Kitchen 9 l/min 6 - 25 l/min
Baths Undersized 165 l Corner 140 l Shower 250 l Standard 225 l Roll Top 205 l
Whirlpool Spa 225 l
Washing Machines 8l/kg6-12l/kg Dishwashers 0.9 l/place 0.8 - 1.6 l/place Toilets Single Flush 6 l Dual Flush 6 l / 3 l
Alternative approach2.14Asanalternativetousingthecalculationsoftware,thesameresultcanbeobtainedfollowingthe
calculationmethodassetoutintheUK’sWater Efficiency Calculator for new Dwellings available to down load from www.Planningportal.gov.uk,copiesofthisarealsoavailablefromthereceptioninSirCharlesFrossard House.
Table 1 Sample Values
WaterEfficiencyCalculator(Guernsey)Regulation23
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Regulation 23
WaterEfficiencyCalculator(Guernsey) Regulation23
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GUERNSEY TECHNICAL STANDARDSThe following documents have been approved andissuedforthepurposeofprovidingpracticalguidance with respect to the requirements of the BuildingRegulations
Guernsey Technical Standard A:Structure,2012editionwithMay2016amendments.
Guernsey Technical Standard B: Fire Safety - Volume1-Dwellinghouses,2012editionwithMay2016 amendments.
Guernsey Technical Standard B: Fire Safety - Volume 2 - Buildings other than dwellinghouses, 2012editionwithMay2016amendments.
Guernsey Technical Standard C: Sitepreparationand resistance to contaminants and moisture 2012editionwithMay2016amendments.
Guernsey Technical Standard D:Toxicsubstances 2012editionwithMay2016amendments.
Guernsey Technical Standard E:Resistancetothepassageofsound,2012editionwithMay2016amendments.
Guernsey Technical Standard F:Ventilation,2012editionwithMay2016amendments.
Guernsey Technical Standard G:Health,hygieneandwaterefficiency,2012editionwithMay2016amendments.
Guernsey Technical Standard H:Drainageandwastedisposal,2012editionwithMay2016amendments.
Guernsey Technical Standard J:Heatproducingappliancesandfuelstoragesystems,2012editionwith May 2016 amendments.
Guernsey Technical Standard K:Safemeansofaccessandegress,2012editionwithMay2016amendments.
Guernsey Technical Standard L1:Conservationof fuelandpower–Dwellings,2012editionwithMay2016 amendments.
Guernsey Technical Standard L2:Conservationof fuelandpower–Buildingsotherthandwellings,2012editionwithMay2016amendments.
Guernsey Technical Standard M:Accesstoanduseofbuildings,2012editionwithMay2016amendments.
Guernsey Technical Standard N:Glazing-Materialsandprotection,2012editionwithMay2016 amendments.
Guernsey Technical Standard P:Roads-Layoutdesignandconstruction,2012editionwithMay2016 amendments.
Guernsey Technical Standard Regulation 11:MaterialsandWorkmanship,2012editionwithMay 2016 amendments.
Crown copyright material is reproduced with the permission of the Controller of HMSO and the Queen’s Printer for Scotland
This Document is available in PDF format for downloading ontheStatesofGuernseywebsitewww.gov.gg
States of Guernsey - Building ControlLa CharroterieSt Peter PortGuernseyGY11FHTelephone +44 (0) 1481 717200Facsimile +44 (0) 1481 717099Email planning@gov.gg
States of GuernseyBuilding Control