san antonio analysis

7/31/2019 San Antonio Analysis

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SanAntonioResidentsBuying2012IECCHomesWillSaveThousands

AnAnalysisofHomeownerProfitafterPayingIncrementalConstructionCosts

ForNewSingleFamilyHomesMeetingtheBuildingEnergyCode

HIGHLIGHTS

• Energycostsavingsfora2012IECChomeareestimatedtobe$248peryear($21permonth),

whencomparedtohomesmeetingthecurrentenergycode.

• Break-evenoninvestment—theadditionaldownpaymentandslightmortgagepayment

increase—occursin11months.

• Afterthebreak-evenpoint,homeownersachieveanetprofit(energysavingslessmortgage

costs)of$205annually.

• 2012IECChomebuyerspocket$5,961innetprofitsoverthelengthofa30yearmortgageterm.

SUMMARY

SanAntonio,TXresidentsbuyingnewsinglefamilyhomesmeetingthe2012InternationalEnergy

ConservationCode(IECC)willpocketbetween$5,961innetenergysavingsovera30yearmortgage

term,accordingtoananalysisofenergysavingsandincrementalconstructioncostsbytheBuildingCodes

AssistanceProjectandICF,International.

Thisreportassessesenergysavingsandincrementalconstructioncostincreasesofnew,2,400squarefoot

singlefamilyhomesinSanAntoniothatmeetthelatestmodelenergycode,the2012IECC,comparedto

thecurrentcodeineffect,the2009IECC.Thisanalysisfindsthatanaveragenewhomemeetingthe2012

IECCwilladdlessthan1%tothecostofanewhome,costinganadditional$939overthecostsofhomes

meetingthecurrentenergycode. Annualenergysavingsfor2012IECChomesaresignificant,andareestimatedinthisstudyatbetween$248peryear.

Theenergysavingsfromthe2012codeareenoughtopaybackthebuyer’sadditionaldownpaymentand

slightlyincreasedmortgagecostinapproximately11months( soonerifthehomebuyerputslessthan20%

down).Afterthatdate,theownercontinuestopocketaprofit(energysavingsminusmortgagecosts)of

$205annually—moneythatwouldotherwisegotopayhigherutilitybills. Thesenetsavingswillbeeven

greaterifenergycostsriseoverthenext30yearsconsistentwithhistoricaltrends.

Stateddifferently,monthlyutilitybillsavingstothehomeowneraremorethanfivetimesasmuchasthe

additionalmortgagepayment neededtocovertheaddedfirst-costofenergysavingfeaturesincludedin

the2012code.

ENERGYSAVINGSANDCONSTRUCTIONCOSTMETHODOLOGY

Tocalculateenergysavingsandincrementalconstructioncosts,thisanalysisdefineda“typical”single

familyhousetorepresentnewresidentialdevelopmentinSanAntonio.Thehomemodeledistwostories

inheight,withexteriordimensionsof30by40feetwithwood-framedwallsandslabongradefoundation.

Themodelhome’ssizeandfoundationtypeisbasedonregionalconstructionpractices,anditcontains



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2,400squarefeetinfloorarea—whichisalsotheapproximatesizeoftheaveragenewhomebuilt

nationwide.

Forthepurposesofthisanalysisweassumeabaselinehomethatmeetstherequirementsofthe2009

IECC,whichisthecity’scurrentcode.Althoughsomeleadingbuildersaremeetingorexceedingmany

elementsofthe2012IECCalready,forpurposesofthisanalysisweassumeabaselinehomethatexactly

meetstherequirementsofthe2009IECC.

EnergysavingsweremodeledbyICFInternational(ICFI),aninternationalenergyconsultingfirmwith

extensiveexperienceintheuseofhourlybuildingenergysimulationsoftwaretoestimateenergy

performanceandenergysavingsofalternativebuildingcodesanddesignconcepts.Althoughthevalues

includedintheanalysisrepresentacareful,independenttechnicaljudgmentbyICFIstaff,itshouldbekept

inmindthat–likeanysuchanalysis–theresultsdependonanumberofassumptionsaboutthephysical

featuresofatypicalnewhome,operatingpractices,energyprices,andotherfactors.

Boththeexisting2009IECCandthenew2012IECCcodesallowabuildertochooseamonganumberof

alternativestocomplywiththecode.Inthiscase,ICFIconservativelychosetocomparetheresultsfrom

theprescriptivepathofeachversionofthecode.ICFIusesBeaconTM,anhourlysimulationmodelthat

utilizesDOE-2orEnergyPlus,andsummarizesbuildingperformanceintermsofestimatedannualenergy

costs,basedonlong-termaverageweatherconditionsinagivenclimatezone(city),DOE/EIAstatelevel

energycosts.ICFIalsoestimatesenergyconsumptionbyend-use,fueltype,electricitypeakdemand,and

airconditionersizeineachprototypehome.Moredetailsofthemodelingassumptionsusedinthis

analysisareavailableonrequest.

INCREMENTALCOSTS

Usingthe2,400squarefootmodelhomeasabaseline,wecalculatedincrementalcostsbyidentifyingthe

buildingcomponentsthatwouldhavetobeupgradedfromthecurrent2009IECC,accordingtothe

prescriptiverequirementsinthe2012IECC.Toestimateincrementalcosts,werelyonconstructioncosts

fromthewell-regarded2012RSMeansContractor’sPricingGuidetoapproximateactualcostsofnewhomeconstruction.Thisresourceisknowntobeconservativeandisusefulforthisanalysisbecauseall

estimatedconstructioncostsareinclusiveofmaterialcosts,labor,andcontractoroverheadandprofit.1

Forthisanalysis,RSMeansdataissupplementedbyadditionalcallstolocalbuildingsuppliersandexperts.

Windows

SanAntoniocontractorswillneedtomakeupgradestoinstalledwindowstomeettheimprovedU-factor

andSHGCfactorsinthe2012IECC.U-factorforwindowsisupgradedfrom0.65underthecurrentcodeto

0.40underthe2012IECCandtheSHGCfactorisimprovedfrom0.30to0.25.Thisaddedcostis

conservativelyestimatedbytheEfficientWindowsCollaborative(EWC)asnomorethan$1.00persquare

footofwindowarea.Itisimportanttonotethatmanybuildersmayalreadyinstallwindowsthatmeetthe

2012IECC’sslightly-improvedrequirements,butinanefforttobeconservative(andstrictlycomparethe

twocodes)thisanalysisassumesthatbuildersarecurrentlyusingtheleast-costwindowtomeetexisting

coderequirements.2Totalwindowincrementalcostsareestimatedas$357.

1RSMeansalsoincludesalocationfactor,whichprovidesanestimateoflocalcostsasapercentageofRSMeans

nationalaverageestimates.Forthisanalysis,thelocationfactorforSanAntoniois79%,indicatingthatconstruction

costsinthecityareapproximately21%lowerthanthenationalaverage.2Asaresult,manybuilderswillbeabletoreduceoravoidincrementalcostsforbetterwindows.



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WholeHouseAirLeakageandVentilation

Weestimatethattheadditionalrequiredairsealinginthe2012IECCandtherequiredtestingforwhole

houseairleakage(commonlyknownas“blowerdoor”)andductleakagewilladdabout$350pernew

home.3Becausetheresultinghomewillhavefewerairandductleakstotheoutside,mechanical

ventilationwillhavetobeimproved,acostweestimateat$180forupgradingonebathroomventfantoa

unitwithanEnergyStarratingalongwiththeinstallationofasimplecontrollerwhichissetto

automaticallyexhaustindoorair.

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HotWaterDistributionLines

Anadditional2012IECCcodechangewillrequirebuilderstoinsulatehotwaterdistributionlinesto

kitchens.Webelievethecostimpactofthischangeissmall,asR-3insulationcostslessthan50centsper

linearfootandmostinsulationproductscanbe“clipped”aroundsupplypipesaftertheplumbingrough-

in.5Asaresult,thiscostisestimatedat$100pernewhome.

LightingandProgrammableThermostats

Builderswillhavetoinstallhigh-efficiencylampsin75percentofhard-wiredfixtures,upfrom50percent

inthe2009IECC.Usually,thisrequirementismetwithcompactflorescentlights(CFLs).Ouranalysis

estimatesthattheupgradeoflampsin25percentoffixtureswillcostnomorethan$25.Builderswillalso

havetoupgradeconventionalthermostatstoprogrammablethermostats,acostwhichisestimatedas

$50.

AtticInsulation

The2012IECCalsorequiresbuilderstoupgradeblown-inceiling(attic)insulationfromR-30toR-38,which

isestimatedbyRSMeanstocostanadditional$284pernewhome.

CostSavings

Fortunately,the2012IECCwillalsointroducecostsavingsforbuilders.Whilecomplyingwiththe2012

IECCincreasesfirst-costinsomeareas,thenewcodealsopresentsopportunitiesto reducecostsforHVAC

equipmentasaresultofanimprovedbuildingenvelope.Amongotherpossiblesavings,builderswillbe

abletoreducethesizeofcostlymechanicalequipment.FortheprototypehouseinSanAntonio’sclimatezone2,builderswillbeabletoreducethecoolingsystemcapacityfromanaverageof48,000kBtuhto

39,000kBtuhorfrom4toapproximately3.5tons.Thisreductioninairconditionercapacitycanresultin

first-costsavingsofone-halfton,whichisexpectedtosaveapproximately$408fortheaveragenew

house.6

3$350isacommonlyusedasanexpectedairsealingandtestingcostfornewsingle-familydetachedhomes

nationwide.4VentilationsystemandcostsaredescribedinanAugust2005reportfromLawrenceBerkeleyNationalLaboratory

“ReviewofResidentialVentilationTechnologies.”Althoughthecostsofthesecomponentshavedecreasedinrecent

years,the2005estimate($180pernewhome)isquotedinthisanalysis.5Itisdifficulttodeterminewhatcombinationofredesign,resizing,and/orpartialinsulationofhotwaterlineswould

bedoneinatypicalnewhome.Insulatingdistributionlinestothekitchenandverylongrunswouldaddcostswhile

downsizinglineswouldreducecosts;inanycasewebelievetheneteffectwouldbesmall.6 EPAconservativelyestimatesfortheirEnergyStarHomesVersion3thatfirst-costsavingsfordownsizinga13SEER

airconditionerare$815perton.By“right-sizing”theHVACequipment,buildingoccupantswillalsobenefitfroma

reductioninequipmentshort-cycling(i.e.,whereequipmentistoolargeforthecoolingloadandcyclesonandoff

frequently,thuswastingenergyandlosingsomeofitsabilitytodehumidifyindoorair).Pleasenotethatadditional

costsavingscouldbeobtainablefromdownsizingheatingequipment,butthisstudydoesnotattempttocalculate

thosesavings.



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TotalincrementalcostsfornewhomesinSanAntonioareestimatedinTable1,below:

Table1:SanAntonio2012IECCIncrementalCosts

BuildingComponent TotalArea Incremental

Cost/SquareFt

Total Location

Factor

AdjustedTotal

CeilingInsulationUpgradefromR-30to

R-38(bothblown-in)

1,200 $0.30 $360 79% $284

UpgradeWindowstoU-0.40andSHGC

0.25

357 $1.00 $357 N/A $357

IncreasedAirSealingandTesting N/A N/A N/A N/A $350

InsulatingHotWaterPipes N/A N/A N/A N/A $100

75%CFLsinhardwiredfixtures(from

50%)

N/A N/A N/A N/A $25

UpgradetoProgrammableThermostats N/A N/A N/A N/A $50

BathroomVentFanUpgradeand

AdditionofAutomaticTimer

N/A N/A N/A N/A $180

HVACSystemSavings(downsizing

coolingsystem1/2ton)

N/A N/A N/A N/A $(408)

IncrementalCost$939

ENERGYCOSTSAVINGS

Accordingtothemodelusedinthisanalysis,upgradingtothe2012IECCwillresultinsignificantenergy

billsavingsforSanAntoniohomebuyers,resultinginutilitybillsavingsof$248peryear .Itisnoteworthy

thatthesesavingsassumeconstantenergyprices;ifenergypricescontinuetoriseconsistentwith

historicaltrends,savingswillbegreaterinfutureyears.Theseenergysavingsallowhomebuyerstoquickly

recapturetheirincrementalcosts.

MORTGAGEPAYBACKFORHOMEOWNERS

Homebuyerswillbeabletoincludetheincrementalfirst-costsofmeetingthe2012IECCintheirmortgage,whilebenefitingfromlowerutilitybillsstartingondayone. Withestimatedenergycost

savingsofbetween$248peryear,monthlyutilitybillsavingsaremorethanfiveasmuchastheadditional

mortgagepaymentneededtocovertheaddedfirst-costofenergysavingfeaturesrequiredbythe2012

IECC.

Thiscash-flowdifferenceisenoughtopaybackthebuyer’saddeddownpaymentwithin11after

purchase(orsooneriftheloanallowsadownpaymentbelow20%). Afterthatdate,theowner

continuestorealizeaprofitofatleast$205annuallyduetolowerutilitybills–andevenmoreifenergy

pricesincrease.

Thispaybackanalysisassumesthathomebuyerspurchaseanewhomewith20%downatthecurrentnationwideinterestrateof4.03percent.Thisscenariowouldresultinanincreaseddownpaymentof$188

withanadditionalmonthlymortgagecostof$4permonth.Takingintoaccountenergysavingsandlower

utilitybills,acashflowanalysisindicatesthatthehomebuyerwouldbreakevenwithin11months.After

thatbreak-evendate,homeownerswouldcontinuetorealizeaprofitof $205annually,whichis

calculatedbysubtractingadditionalmortgagecostsfromenergysavings.Homebuyerswithalowerdown

payment—suchas5or10percent—willrealizepaybackmorequickly.Mortgagepaybacktohomeowners

ispresentedbelowinTable2,below.



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Table2:MortgagePaybackforHomebuyers

Home

Description

Incremental

Costs

Energy

Savings/Year

andMonth

perhome

DownPayment

Increase(and

Mortgage

Increaseper

Month)

Breakeven

Point

AnnualProfitfor

Homeowner

afterBreakeven

Point

GrossProfitover

MortgageTerm

(EnergySavings

MinusMortgage

Costs)

2012IECCHomeinSan

Antonio

$939 $248/year($21/month)

$188(plus$4/month)

11months $205

$5,961

CONCLUSIONS

• Asestimatedinthisanalysis,incrementalcostsfornew2,400squarefoothomesbuilttothe2012

IECCinSanAntoniototal$939pernewhome.

• AnnualenergysavingsforSanAntoniohomeownersattributabletothe2012IECCare$248.

• Assumingaconservative20%downpayment,newhomebuyerswillbreakevenontheirinitial

investmentinnomorethan11monthsafterpurchase.• Grossprofitforhomebuyersovera30yearmortgagetermis$5,961.

AboutBCAP

Asanindependentjudgeoftheefficacyofenergycodes,BCAPstrivestousedatatoaddressenergycode

barriers,includingtherealorperceivedconstructioncostsincurredbycodechanges.Toaddressconcern

inthebuildingcommunitythatupgradingtothelatestversionoftheresidentialenergycode,the2012

IECC,willresultincostprohibitiveincreasesinconstructioncostfornewsingle-familyhomes,BCAPhas

completedanationwideincrementalcostanalysisaswellasanalysisforstatesondemand.BCAPisa

projectoftheAlliancetoSaveEnergy,anonprofitorganizationthatpromotesenergyefficiencyworldwidethroughresearch,education,andadvocacy.

ContactInformation:

2012IECCAdoptionandEnergyCodesPolicy WilliamD.Fay MaureenGuttman,AIA ExecutiveDirector ExecutiveDirector,BuildingCodesAssistanceProject

EnergyEfficientCodesCoalition SeniorDirector,BuildingsPrograms

(202)530-2214 AlliancetoSaveEnergy

[email protected] (202)530-2211 [email protected]

TechnicalAnalysisJohnMiller MikeDeWein

ProjectManager TechnicalDirector BuildingCodesAssistanceProject BuildingCodesAssistanceProject

(202)530-4340(direct) (518)664-1308(direct) [email protected] [email protected]

san antonio analysis

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