1407 PACIFIC HIGHWAY, WARRAWEE€¦ · ALTERNATIVE SOLUTION REPORT – 1407 Pacific Highway,...
Transcript of 1407 PACIFIC HIGHWAY, WARRAWEE€¦ · ALTERNATIVE SOLUTION REPORT – 1407 Pacific Highway,...
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JSquaredEngineeringPty.Ltd.ACN605793986
FIRESAFETYENGINEERING|ESSENTIALSERVICESMAINTENANCEMANAGEMENT|BUILDINGSERVICESDESIGN
NSWOffice-POBox169,JindabyneNSW2627,Phone:0264561285,Mobile:0427571420
SAOffice-POBox146,MagillSA5072,Phone:0883900462,Mobile:0412882122
1407PACIFICHIGHWAY,WARRAWEEFIREENGINEERINGREPORTDEVELOPEDINACCORDANCEWITHTHEPERFORMANCEREQUIREMENTOFTHEBCA
• PROTECTIONOFOPENINGS• EXTENDEDTRAVELDISTANCES• REDUCTIONINFIRERESISTANCELEVELS• FIREHYDRANTPUMPROOM
DATE:15JUNE2017REPORTNO:0379-REVAFINALPREPAREDFOR:BAINIDESIGNPREPAREDBY:J2CONSULTINGENGINEERS|FIRESAFETYENGINEERING
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CONTENTS
EXECUTIVESUMMARY&RECOMMENDATIONS........................................................................................4REQUIREMENTSOFALTERNATIVESOLUTION..........................................................................................4
1.0INTRODUCTION............................................................................................................................................61.1BasisoftheReport...................................................................................................................................................61.2PurposeoftheReport.............................................................................................................................................61.3LimitationsoftheReport.......................................................................................................................................71.4AssumptionsoftheReport....................................................................................................................................7
2.0FIREENGINEERINGBRIEF.........................................................................................................................82.1RelevantStakeholders............................................................................................................................................82.2BuildingandOccupantCharacteristics.............................................................................................................82.3Hazards,PreventativeandProtectiveMeasuresAvailable.......................................................................92.4DirectlyrelevantIFEGSub-Systems................................................................................................................11
3.0ALTERNATIVESOLUTION1–PROTECTIONOFOPENINGS..........................................................123.1Deemed-to-SatisfyProvisions...........................................................................................................................123.2DetailsofBCADTSDeviation.............................................................................................................................123.3RelevantPerformanceRequirement..............................................................................................................133.4AssessmentMethodology...................................................................................................................................133.5AcceptanceCriteria...............................................................................................................................................143.6QualitativeandQuantitativeAssessment.....................................................................................................153.7AssessmentagainstrelevantPerformanceRequirement.......................................................................163.9AssessmentConclusion.......................................................................................................................................17
4.0ALTERNATIVESOLUTION2–EXTENDEDTRAVELDISTANCES..................................................184.1Deemed-to-SatisfyDeviation.............................................................................................................................184.2DetailsofAlternativeSolution..........................................................................................................................184.3RelevantPerformanceRequirements............................................................................................................184.4AssessmentMethodology...................................................................................................................................194.5AcceptanceCriteria...............................................................................................................................................194.6QualitativeAssessment.......................................................................................................................................194.7AssessmentagainstrelevantPerformanceRequirement.......................................................................214.8AssessmentConclusion.......................................................................................................................................22
5.0ALTERNATIVESOLUTION3–REDUCTIONINFIRERESISTANCELEVELS................................235.1Deemed-to-SatisfyNon-compliance................................................................................................................235.2DetailsofBCADTSDeviation.............................................................................................................................236.3RelevantPerformanceRequirement..............................................................................................................235.4AssessmentMethodology...................................................................................................................................245.5AcceptanceCriteria...............................................................................................................................................245.6QuantitativeAssessment....................................................................................................................................255.7AssessmentagainstrelevantPerformanceRequirement.......................................................................255.8AssessmentConclusion.......................................................................................................................................26
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6.0ALTERNATIVESOLUTION4–FIREHYDRANTPUMPROOM........................................................276.1Deemed-to-SatisfyNon-compliance................................................................................................................276.2DetailsofBCADTSDeviation.............................................................................................................................276.3RelevantPerformanceRequirement..............................................................................................................286.4AssessmentMethodology...................................................................................................................................286.5AcceptanceCriteria...............................................................................................................................................286.6QualitativeAssessment.......................................................................................................................................296.7AssessmentagainstrelevantPerformanceRequirement.......................................................................306.8AssessmentConclusion.......................................................................................................................................30
7.0CONCLUSIONS..............................................................................................................................................317.1Conclusion................................................................................................................................................................317.2SpecificationoftheFinalTrialDesign............................................................................................................317.3MaintenanceRequirements...............................................................................................................................317.4RequirementsoftheAlternativesolution....................................................................................................31
8.0REFERENCES................................................................................................................................................32AppendixA–DataRelieduponintheFEB/RProcess..........................................................................32CommonAbbreviationsUsedinFireEngineering............................................................................................33ClientDesignandBuildingRegulatoryObjectives............................................................................................33MethodsofAnalysis.....................................................................................................................................................34RelevantIFEGSub-Systems.......................................................................................................................................34AcceptanceCriteriaandFactorsofSafetyfortheAnalysis............................................................................35ApproachesandMethodsofAnalysis....................................................................................................................37ConstructionandCommissioningRequirements..............................................................................................37
REVISION STATUS REPORT No. & REVISION DATE STATUS WRITTEN CHECKED 0359 REV A 17/01/17 DRAFT
JS JA
0359 REV A 15/06/17 FINAL
JS JA
COMMERCIAL IN CONFIDENCEThis document contains confidential material that is intended solely for J2 Engineering Pty. Ltd.. The project team and all regulatory authorities shall exercise precautionary measures to ensure that the information contained herein is not to be accessed by any third party. J2 Engineering Pty. Ltd will take no responsibility for the use of any information contained within this report by any third party.
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EXECUTIVESUMMARY&RECOMMENDATIONS
J2 Fire Engineers have been commissioned to carry out a fire safety engineering analysis and assessment of theproposedapartmentdevelopmentlocatedat1407PacificHighway,Warrawee.ThisreportprovidesaFireEngineeredAlternativeSolutiondevelopedtopermitthefollowingBCAnon-compliancesinthesubjectbuilding.AlternativeSolutions BCA DTS
ProvisionBCAPerformanceRequirement
AssessmentMethodology
Topermitwindowopeningstobelocatedmarginallylessthan3mfromthesideallotmentboundarywithoutrequiringprotectionaspertherequirementsofBCAC3.4.
C3.2,C3.4 CP2 QualitativeandquantitativeassessmentdemonstratingcompliancewiththeperformancerequirementsunderA0.3(a)(i)viaaperformancebasedapproachpermittedunderA.05(b)(ii).
Topermitextendedtraveldistancesofupto8.8mtoasingleexitservingtheapartmentsontheupperlevelsofthebuilding.
D1.4 DP4,EP2.2 QualitativeassessmentdemonstratingcompliancewiththeperformancerequirementsunderA0.3(a)(i)viaaperformancebasedapproachpermittedunderA.05(b)(ii).
Topermitareducedslabthickness(setdownof30mmtoallowfortilebeds)toachievetherequiredFRLof120/120/120or90/90/90dependingonthelocationofthesetdown.
B1.4,Spec.C1.1
CP1,CP2 QualitativeassessmentdemonstratingcompliancewiththeperformancerequirementsunderA0.3(a)(i)viaaperformancebasedapproachpermittedunderA.05(b)(ii).
Topermitthefirehydrantpumproomtobeaccessedviaastairwaynotcontainedinafireisolatedshaft.
E1.3 EP1.3 QualitativeassessmentdemonstratingcompliancewiththeperformancerequirementsunderA0.3(a)(i)viaaperformancebasedapproachpermittedunderA.05(b)(ii).
REQUIREMENTSOFALTERNATIVESOLUTION
Considering the relevant provisions of the BCA, the Alternative Solution, subject to the provision of the followingrequirements,isconsideredtomeetandcomplywiththePerformanceRequirementCP1,CP2,DP4,EP1.3andEP2.2:
AlternativeSolution11. Bedroomwindows1and2withinunitsG.1,1.1and2.1shallbeprovidedwithmetallicflyscreens,suitablefor
use in bushfire prone areas as per the requirements of AS3959, with maximum 2mm aperture size.Alternatively,thesewindowscanbefixedintheshutposition.
2. Bedroomwindows2and3,andthebathroomwindowwithinunitsG.4and1.4shallbeprovidedwithmetallicflyscreens,suitableforuseinbushfireproneareasaspertherequirementsofAS3959,withmaximum2mmaperturesize.Alternatively,thesewindowscanbefixedintheshutposition.
3. Bedroom windows 1 and 2, and the bathroom window within unit 2.4 shall be provided with metallic flyscreens, suitable for use in bushfire prone areas as per the requirements of AS3959, withmaximum 2mmaperturesize.Alternatively,thesewindowscanbefixedintheshutposition.
AlternativeSolution24. Theentrydoorwaystothestairwaysonlevels1and2shallbeconfiguredasself-closingsmokedoorswhich
shallbeprovidedwithmediumtemperaturesmokeseals.Theconstructionaroundthewallsandceilingshallberesistanttothepassageofsmokethroughsealingofanypenetrationsthroughthewall/ceilingconstructionofthestairwayonthesetwoupperlevels.
5. ThedoorwaysopeningintothelobbyfromtheSOUsandservicesroomonthegroundfloorshallbeprovidedwithmediumtemperaturesmokeseals.
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AlternativeSolution36. Theminimumslabthicknessatthepointofsetdownmustnotbelessthan150mmatanylocation.7. Theminimumconcretecoveronanysteelreinforcementbarsrunninghorizontallywithintheslabshallnotbe
lessthan30mm.
AlternativeSolution48. The fire hydrant pump room shall be provided with fire rated construction achieving a minimum FRL of
120/120/120withtheentrydoorwayachievingaminimumFRLof-/120/30.9. The wall bounding the carpark and the stairway/corridor leading to the fire isolated stairway shall be
provided with fire rated construction achieving a minimum FRL of 120/120/120 with the exit doorwayachievingaminimumFRLof-/120/30.
10. Thefirehydrantpumpshallbeautomaticallyoperatedfromapressureswitch,flowswitchorsimilar.Maintenance11. The recommendations of this reportmust form part of the fire safety certificate and the annual fire safety
statement for the building to ensure the recommendations of this report are compliedwith throughout thebuildingoperation.
TheAlternativeSolutionhasbeendevelopedusingcomparisonwiththeDeemed-to-SatisfyProvisionsandaqualitativeandquantitativeassessment, and is considered to complywithBCAPerformanceRequirementCP1,CP2,DP4,EP1.3andEP2.2.TheBCArecognisestheseAssessmentMethodasacceptablemethodsfordeterminingthattheAlternativeSolutionsatisfiesthePerformanceRequirementinaccordancewithBCAClausesA0.3(a)(i)andA0.5(b)(ii).
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1.0INTRODUCTION
J2 Fire Engineers have been commissioned to carry out a fire safety engineering analysis and assessment of theproposedapartmentdevelopmentlocatedat1407PacificHighway,Warrawee.ThisreportprovidesaFireEngineeredAlternativeSolutiondevelopedtopermitthefollowingBCAnon-compliancesinthesubjectbuilding.
• Topermitwindowopeningstobelocatedmarginallylessthan3mfromthesideallotmentboundarywithoutrequiringprotectionaspertherequirementsofBCAC3.4.
• Topermitextendedtraveldistancesofupto8.4mtoasingleexitservingtheapartmentsontheupperlevelsofthebuilding.
• Topermitareducedslabthickness(setdownof30mmtoallowfortilebeds)toachievetherequiredFRLof120/120/120or90/90/90dependingonthelocationofthesetdown.
• Topermitthefirehydrantpumproomtobeaccessedviaastairwaynotcontainedinafireisolatedshaft.Thisreportdemonstratesthatupontheadoptionofsuitablealternativesolutions,asdetailedintheExecutiveSummaryofthereport,therelevantPerformanceRequirementoftheBuildingCodeofAustralia(BCA)willbemet.
1.1BasisoftheReport
ThisAlternativeSolutionReportisbasedonadesktopassessmentofthefollowingdocumentation:
• BuildingCodeofAustralia2016,publishedbytheAustralianBuildingCodesBoard(ABCB)• InternationalFireEngineeringGuidelines2005,publishedbyAustralianBuildingCodesBoard(ABCB)• TheGuidetotheBCA2016,publishedbytheAustralianBuildingCodesBoard(ABCB)• ArchitecturaldetailspreparedbyBainiDesignasfollows:
DrawingNumber Revision01 B03 B04 B05 B06 B07 B08 B09 B10 B11 B
PreparationoftheAssessmentReportwillsatisfytherelevantPerformanceRequirementsoftheBCAthroughabsoluteassessmenttechniques.
Nootheraspectsorpartsofthebuildingapartfromthealternativesolutionsasoutlinedabovewillbeassessedandtheremainderof theproposeddevelopment isassumedtocomplywith therelevantDTSprovisionsor thePerformanceRequirementoftheBCA.
1.2PurposeoftheReport
Thisreporthasbeenpreparedtoaddressnon-compliancematterswith theDeemed-to-SatisfyProvisionsof theBCA(as tabled in the Executive Summary), and to provide an Alternative Solution developed in accordance with theprovisionsoftheBCA.Thepurposeof this report is todemonstrate that theproposeddevelopmentwill satisfyPerformanceRequirementsCP1,CP2,DP4,EP1.3andEP2.2asthedesignisatleastequivalenttotherelevantDeemed-to-SatisfyprovisionsoftheBCAand/orsatisfiesthePerformanceRequirementoftheBCA.
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This report is prepared for the purposes of submitting to the Certifying Authority (CA) for acceptance prior to theissuingofaConstructionCertificaterelevanttotheproposal.
1.3LimitationsoftheReport
Thisreportexcludesanyworksnotoutlinedabove,howeverspecificallyexcludesthefollowing:• Determining full compliancewith theBCA,other than thematters identified in theexecutive summaryof this
report;• AddressinganymattersthatareoutsidethescopeorlimitationsoftheBCA;• AmendmentstotheAlternativeSolutionBriefduetodesignchangesorincapacitytocomplywiththeTrial
Designs;• IssuingofanyPart4AcertificatespursuanttotheEnvironmentalPlanningandAssessmentAct1979.Thisreport
isnotaPart4AcompliancecertificateundertheEnvironmentalPlanning&AssessmentAct1979orRegulation2000;
• Considerationofanyfireservicesoperations(includinghydraulic,electricalorothersystems);• Consideration of any structural elements or geotechnical matters relating to the building, including any
structuralorotherassessmentoftheexistingfireresistancelevelsofthebuilding;• ThisreportdoesnotprovideconcessionsforanyAlternativeSolutionorexemptionsfromtherequirementsof
theBCA,otherthanthatidentifiedintheExecutiveSummaryofthisreport;• DeterminingcompliancewiththeDisabilityDiscriminationAct1992orPartD3oftheBCA;• Reportingonhazardousmaterials,OH&Smattersorsitecontamination;• Anyenergyefficiencyassessment;howeverifnecessary,proposalscanbeobtainedfromsuitablyqualifiedand
accreditedassessors.
1.4AssumptionsoftheReport
This report provides an Alternative Solution for the Deemed-to-Satisfy non-compliance identified in the ExecutiveSummary.Theremainderof thebuilding isassumedtocomplywiththeDeemed-to-SatisfyProvisionsof theBCAforthepurposeofthisreport.Thereportisprovidedonthebasisthat:• TheAlternativeSolutiononlyappliestopropertydetailedinsection2.2.• TheAlternativeSolutionisapplicabletothedesigndocumentationprovidedforassessmentandaslistedin• Section 1.1. Any future alteration, enlargement or addition will require re-assessment to determine the
applicationofthissolutiontothosechanges.• TheBuildingwill generally complywith theDeemed-to-Satisfy Provisions of theBCA, exceptwheremodified
specificallybythisreport.• It is assumed that the building will be subject to ongoing annual maintenance and the fire safety measures
requiredbythisreportandtheBCAwillbemaintainedtoastandardnotlessthantheirinstallationstandard.
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2.0FIREENGINEERINGBRIEF
The development of this report follows a consultative process with the Certifying Authority and the Developer’sRepresentative. In lieu of submitting a formal Fire Engineering Brief (FEB) for this project, the proposed fireengineeringassessmentwasdiscussedandagreeduponwiththecertifyingauthoritypriortocompletionofthisreport.FurtherdetailsofthedatarelieduponintheFEB/FERprocessaredetailedinAppendixA.
2.1RelevantStakeholders
Stakeholder/Role NameCertifyingAuthority CertifiedBuildingSpecialistsArchitect BainiDesign–RomanTalatoFireEngineer J2ConsultingEngineers–JamesSunjaya,James
Alexander
2.2BuildingandOccupantCharacteristics
GeneralBuildingCharacteristics
BuildingCharacteristic DescriptionOccupancy/UseBuildingClass/es:Typeofconstruction:StoreysContained;RiseinStoreys:EffectiveHeight:
ResidentialunitsandassociatedcarparkingonthebasementlevelsClass2,7aTypeA4411.7m
Location:Generaldescriptionofdevelopment:
1407PacificHighway,WarraweeThedevelopmentproposestoconstructthreestoreysofapartmentsatopabasementlevelcarparkassociatedwiththeapartmentbuildingabove.
OccupantCharacteristics
OccupantCharacteristic DescriptionTypeandnumber Occupants would generally be expected to be capable of caring for themselves
consistent with residential housing use. It is not anticipated that more than acombined50peoplewouldnormallyinhabitthetwelveresidences.
Occupantstate Building occupants could be both awake and asleep. Occupants may also beintoxicatedorsober.Occupantsonalllevelswouldbeexpectedtohaveareasonablelevelofmobilitytocomfortablynegotiatethestairsaccessonaday-to-daybasis.
Physical and mentalattributes
Themajority of occupants are considered to bemobile and ambulatory. Given thebuilding contains only fourteen units it is possible that a relationship will existbetween occupants, which would not normally be the case in a multi-storeyresidentialunitdevelopment.
Assistancerequired/available
Itwillbelikelythatassistancewillnotberequiredastheoccupantswillbefamiliarwiththelocationoftheexitsandthepathstotheexitsgiventhesimplelayout.TheassistanceavailablewillbeintheformoftheBuildingOccupantWarningSystem
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OccupantCharacteristic Descriptiontohelpoccupantsinanevacuation.Assistancemayalsobeprovidedfromotherablebodiedoccupants.
TrainingandRoles Occupantsareconsideredtohavelimitedtrainingorexperience.Hazards Kitchencookingareas.
Occupantssmokinginapartments.Electricalequipmentlocatedincorridorsprovidingelectricitytotheresidentialpartsaswellascommunicationscablingandequipment.Carrelatedfireinthebasementcarpark.
2.3Hazards,PreventativeandProtectiveMeasuresAvailable
Thefollowinghazardshavebeenidentifiedinthesoleoccupancyunits.Hazard Details/Precaution
GeneralLayoutandDesign Nohazardsidentifiedwithdesign.Activities Informationisnotavailabletosuggestthatactivitiesoutsidethose
normally undertaken in residential house will be carried out andhencethehazardisnotconsideredtobeincreased.
Cooking - NSWFB statistical dataindicates that these firesmake up 33%ofallreportedresidentialfires.(NSWFB2001/2002)
A smoke alarm or detection system would notify occupants torespond to cooking fire outbreaks if unattended. If the outbreakdevelops beyond that controllable occupants are required toevacuate.
Occupants smoking in Sole OccupancyUnits (SOU’s). NSWFB statistical dataindicates that fires in sleeping areasmakeup44%ofallreportedresidentialfires. These predominantly includesmokinginbedandcombustiblesplacedupon or near heaters. (NSWFB2001/2002)
A smoke alarm or detection system would notify occupants torespond to smoking related fire outbreaks if unattended. If theoutbreakdevelopsbeyondthatcontrollableoccupantsarerequiredtoevacuate.
Electrical equipment failure located inSOU’s,concealedspacesorcarpark.
SOUhabitablespaceA smoke alarm or detection system would notify occupants torespond to electrical fires. If the outbreak develops beyond thatcontrollableoccupantsarerequiredtoevacuate.ConcealedspacesTheroofvoidhazardislimitedtodownlightsandelectricalwiringasanignitionsourcewhichmakesupaverysmallpercentageofthenumber firestartsaccordingtheNSWFBstatisticaldata,hencetheroofvoidhazardisconsideredlow.CarparkandcommonareasElectrical failure is limited to Power outlets lighting and garagedoorfunctionsinthecarpark.Consideredaverylowlevelofhazard.
Multiple arson attack, malicious acts,andactsofterrorism.
The resulting impact of fires from these hazards has not beenaddressedinthisreportastheyarebeyondthescopeoftheBCA.
Thehazardsthatarepresentinthebuildinghavebeenremovedorreducedbysixsub-systemsofpreventativeandprotectivemeasures.Sub-System PresentinBuilding/Requirements
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Sub-System PresentinBuilding/Requirements
AFireinitiation,development
andcontrol
Fire loads or heat release rates are not proposed to be in excess of a normalresidentialunitoccupancyandhence firedevelopmentwillnotbeabnormallyfast.
BSmokedevelopment,spread
andcontrol
DTScompliantboundingconstructionbetweenSOU’swillpreventsmokespreadtoneighbouringunits.Theenclosingofthestairintoashaftassistsinimprovingtenabilityconditionsforbuildingoccupantsseekingegressintheeventofafire.
CFirespread,impactand
control
Fire separation between the SOU’s is compliant and provides an FRL of90/90/90 between units. Minor setdowns in the slab for the wet areas areprovidedwhich are addressedwithin an alternative solution containedwithinthisreport.
DFiredetection,warningand
suppression
An AS1670.1 smoke detection system or AS3786 smoke alarms will notifyoccupants toa fireoutbreak.Occupantsof theunit are likely tobenotifiedbyotheroccupantswithintheunitviaverbalcommunicationintheeventthattheyarelocatedremotefromthefire.
EOccupantevacuationand
control
Exitstoopenspaceareavailablefromeachunitwithoutpassingthroughorbyunprotectedopeningsoftheotherunit.
FFireservicesintervention
ThebuildingisservedbyfulltimefirebrigadepersonnelattheHornsbyNSWFBstationwhichislocated5.0kmfromthesite.Onthisbasis,itisconsideredthatfire services intervention is likely exceed or at least equivalent to mostresidentialareasinsuburbanSydneymetropolitanarea. Thedirectionstositefromthestationcanbeseeninthefigurebelow.
The nearest alternate fire station is the Gordon fire station which is located5.2kmfromthesite.
*InternationalFireEngineeringGuidelines2005(IFEG)Sub-systemA –FireInitiationandDevelopmentandControlSub-systemB –SmokeDevelopmentandSpreadandControlSub-systemC –FireSpreadandImpactandControlSub-systemD –FireDetection,WarningandSuppressionSub-systemE –OccupantEvacuationandControlSub-systemF –FireServicesIntervention
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2.4DirectlyrelevantIFEGSub-Systems
ThedirectlyrelevantIFEGsub-systems(SS)forthisanalysisare:IFEGSub-System Description SymbolSub-systemBSmokeDevelopment,SpreadandControl
• Smokesealsondoorsenteringstairway
Sub-systemCFireSpreadandImpactandControl
• Solidcoredoorsfittedwithself-closersfittedtoegressstairwayEnsuring minimum concrete cover is retained oversteelreinforcement.
Sub-systemFFireServicesIntervention
• Fire rating of doorset leading to corridor to protectfirefightersfromtheeffectsoffirewithinthecarparkareaofthebuilding.
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3.0ALTERNATIVESOLUTION1–PROTECTIONOFOPENINGS
AnalternativesolutionhasbeendevelopedtoaddresstheproposeddeviationfromtheDTSprovisionsofC3.2relatingtoallowingopeningswithinawallrequiredtoachieveafireresistanceleveltoremainunprotectedwithoutprovisionofwindowwettingfiresprinklers(asrequiredtosatisfyclauseC3.4).Thesolutionproposestoconsiderthesizeofthewindowopeningsandthesetbackofthewindowsfromtheboundarywhichappeartobemarginallylessthan3mfromtheadjacentsiteallotmentboundarywhenscaledofffloorplans.
3.1Deemed-to-SatisfyProvisions
ThefollowingDTSprovisionshavebeenidentifiedasbeingsubjecttothealternativesolution: C3.2ProtectionofopeningsinexternalwallsOpeningsinanexternalwallthatisrequiredtohaveanFRLmust—(a)ifthedistancebetweentheopeningandthefire-sourcefeaturetowhichitisexposedislessthan—
(i)3mfromasideorrearboundaryoftheallotment;or(ii)6mfromthefarboundaryofaroad,river,lakeorthelikeadjoiningtheallotment,ifnotlocatedinastoreyatorneargroundlevel;or(iii)6mfromanotherbuildingontheallotmentthatisnotClass10,beprotectedinaccordancewithC3.4andifwall-wettingsprinklersareused,theyarelocatedexternally;and
(b)ifrequiredtobeprotectedunder(a),notoccupymorethan1/3oftheareaoftheexternalwallofthestoreyinwhichitislocatedunlesstheyareinaClass9bbuildingusedasanopenspectatorstand.C3.4Acceptablemethodsofprotection(a)Whereprotectionisrequired,doorways,windowsandotheropeningsmustbeprotectedasfollows:
(i)Doorways—(A)internalorexternalwall-wettingsprinklersasappropriateusedwithdoorsthatareself-closingorautomaticclosing;or(B)–/60/30firedoorsthatareself-closingorautomaticclosing.
(ii)Windows—(A)internalorexternalwall-wettingsprinklersasappropriateusedwithwindowsthatareautomaticclosingorpermanentlyfixedintheclosedposition;or(B)–/60/–firewindowsthatareautomaticclosingorpermanentlyfixedintheclosedposition;or(C)–/60/–automaticclosingfireshutters.
(iii)Otheropenings—(A)excludingvoids—internalorexternalwall-wettingsprinklers,asappropriate;or(B)constructionhavinganFRLnotlessthan–/60/–.
(b)Firedoors,firewindowsandfireshuttersmustcomplywithSpecificationC3.4.
3.2DetailsofBCADTSDeviation
In accordance with C3.2(a)(i) and C3.4(a)(ii), window openings within an external wall required to achieve a fireresistancelevelmustbeprotectedwithwindowwettingsprinklersandbefixedclosed/automaticclosingorachieveafireratingthroughothermeans.Inthisinstance,itisproposedtopermitwindowslocatedatnonearerthan2.9mfromthesideallotmentboundarytoremainunprotectedwithintheclass2building.Theextentofexposedwindowscanbeseeninthefigurebelow.
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Figure1–ApartmentExposurestoEasternBoundaryShadedBlue(2.9mfromBoundary)
As is evident, there are a seriesofwindows locatedwithin3mof theboundarywhichwill be addressedwithin thisalternativesolution.
3.3RelevantPerformanceRequirement
PursuanttoA0.10(b)ofBCAthefollowingperformancerequirementhasbeenidentifiedasbeingdirectlyrelevanttotheDTSprovisionsidentifiedinSection3.1above:CP2(a)Abuildingmusthaveelementswhichwill,tothedegreenecessary,avoidthespreadoffire-
(i) toexits;and(ii) tosole-occupancyunitsandpubliccorridors;and(iii)betweenbuildings;and(iv)inabuilding
(b)Avoidanceofthespreadoffirereferredtoin(a)mustbeappropriateto-(i) thefunctionoruseofthebuilding;and(ii)thefireload;and(iii)thepotentialfireintensity;and(iv)thefirehazard;and(v) thenumberofstoreysinthebuilding;and(vi)itsproximitytootherproperty;and(vii)anyactivefiresafetysystemsinstalledinthebuilding;and(viii)thesizeofanyfirecompartment;and(ix)firebrigadeintervention;and(x) otherelementstheysupport;and(xi)theevacuationtime.
3.4AssessmentMethodology
In order to address the provisions of the BCA, a performance based approach will be adopted to demonstratecompliance of the Alternative Solution with the BCA. The proposed Alternative Solution will review the proposedsolutionusingquantitativeandqualitativemeasuresagainsttherequirementsofCP2.ThequantitativeassessmentwillassesscomplianceagainstBCAverificationmethodCV1.
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3.5AcceptanceCriteria
Itmustbeacceptedthattheopeningsaresuchthatfirespreadtoorfromtheboundaryoradjacentfiresourcefeatureisnotpromoted.IftheproposedalternativesolutioncandemonstratethattheopeningsarenotlikelytoresultinfirespreadviaopeningsintheadjacentbuildingthealternativesolutionwillbeconsideredtosatisfytherequirementsofCP2throughqualitativeandquantitativeabsoluteassessment.Quantitatively,itmustbeacceptedthattheproximityoftheunprotectedwindowsdoesnotpromoteincreasedriskoffire spread between each building and/or the property boundary. If the proposed alternative solution is capable ofdemonstrating that fire spread is unlikely to occur, it will be considered that the solution adequately satisfies theperformancerequirementsoftheBCA.FireSpreadtoBoundaryTheradiantheatfluxcriteriaforfirespreadtoboundariesissetoutintableCV1oftheBCAwhichstatesthat‘abuildingwill not cause heat flux in excess of those set out in column 2 of Table CV1 at locations within the boundaries of anadjoiningpropertysetoutincolumn1ofTableCV1whereanotherbuildingmaybeconstructed’.Column1 Column2Location HeatFlux(kW/m2)OnBoundary 801mfromboundary 403mfromboundary 206mfromboundary 10FireSpreadfromBoundaryFurthertothis,CV1statesthatwhenabuildingis‘locatedatthedistancesfromtheallotmentboundarysetoutincolumn1ofTableCV1,abuildingiscapableofwithstandingtheheatfluxsetoutincolumn2ofTableCV1withoutignition’.Itwillconservativelybeassumedthatallfireshaveachievedflashoverconditions.Inordertodeterminewhetherornotfirespreadhasoccurred,itisproposedtoutilisethefollowingradiantheatfluxcriteriawhichoutlinetherequiredlevelorradiantheatfluxtocausetheignitionofcellulosicmaterials(pilotedandnon-piloted)(Drysdale1998).
Figure2–RadiantHeatRequiredforPilotedandNon-PilotedIgnition
Ifitcanbedemonstratedthatignitionisnotcapableofoccurringviaaquantitativeanalysis,therequirementsofCP2willbeconsideredtobeachieved.
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3.6QualitativeandQuantitativeAssessment
FireSpreadtoBoundaryTableCV1oftheBCAoutlinesthemaximumradiantheatfluxespermittedtobereceivedattheboundary,1montheoppositesideoftheboundary,3montheoppositesideoftheboundaryand6montheoppositesideoftheboundaryfromawindow in the subject building. These radiant heat fluxes are 80kW/m2, 40kW/m2, 20kW/m2 and10kW/m2respectively.Calculationsundertakenindicatethatutilisingsimpleradiantheattransfercalculationsfromaflashoverfireburningat1,000˚C inthesubjectbuilding, thefollowing levelsofradiantheatarereceivedattheboundaryfromeachapartmentwindowlocatedat2.9mfromthesideallotmentboundary.Forthepurposesofcalculation,ithasbeenconservativelyassumedthatallwindowsfromeachapartmentaresimultaneouslyradiatingtowardstheboundary.Unit Window Width(m) Height(m) Setbackto
Centre(m)HeatFlux(kW/m2)atDistancesasListedAtboundary
1m fromboundary
3m fromboundary
6m fromboundary
UnitsG.1,1.1or2.1
Bed1Bed2
2.42.4
0.70.7
2.92.9
9.7
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Level Window TypeofOpening Width(m) Height(m) Setback(m) RadiantHeatReceived(kW/m2)
Unit2.4
Bed1Bed2Bath
DistanceUnknown.Assumedthatopeningis1mawayfromboundaryandhasdimensionsof12mlongby1.28minheight.
12m 1.28m 2.9fromboundaryand3.9fromradiator
22.3
Thetransmittedradiantheatfluxfromtheboundaryradiation(kW/m2)receivedatthewindowopeningswithinthreemetresoftheboundaryfromafireattheboundaryaredetailedinthetableabove.As per the above it can be seen that the radiant heat received at all of the assessedwindow openings exceed thatrequired for piloted ignition of the aluminium framedwindows (12.0kW/m2) as outlined in the acceptance criteriaabove.Theradiantheatfluxishowever,insufficienttoresultinnon-pilotedignition(occurringat28.0kW/m2)andonthisbasisitisproposedtoeitherfixthesewindowsintheshutpositionorprovideemberresistantmetallicflyscreensoverthewindowsthatwillpreventpilotedignitionfromoccurring.Onthebasisofthecalculationsundertakenabove,itisconsideredthattherelevantperformancerequirementCP2hasbeensatisfiedforopeningsfacingtheboundariesprovidingtheaffectedwindowsasscheduledaboveareprovidedwithemberresistantmetallic fly screens thatpreventember ingress.Thesescreensshallbeapproved foruse inbushfireproneareasaspertherequirementsofAS3959.
3.7AssessmentagainstrelevantPerformanceRequirement
The following table summarises the proposed qualitative assessment against the relevant performance requirementCP2.
CP2 (a)Abuildingmusthaveelementswhichwill,tothedegreenecessary,avoidthespreadoffire-
(i)toexits;and Notapplicabletothisalternativesolution.(ii) to sole-occupancy units and publiccorridors;and
Notapplicabletothisalternativesolution.
(iii)betweenbuildings;and The analysis demonstrates that a fire in the building will not result inradiantheatfluxesinexcessofthatoutlinedinverificationmethodsCV1and CV2 when fitted with metallic ember resistant screens withmaximum2mmaperturesize.
(iv)inabuilding Notapplicabletothisalternativesolution.(b)Avoidanceofthespreadoffirereferredtoin(a)mustbeappropriateto-
(i) the function or use of the building;and
Asoutlinedabove, thebuilding is considered tobea typical class2 lowriseapartmentbuildingwithoccupantsgenerallybeingfamiliarwiththelocationoftheexit(astheexitisformedbythefrontentrydoorway).
(ii)thefireload;and Asoutlinedabove,thefireloadisconsideredtobeequivalentto(aclass2building.
(iii)thepotentialfireintensity;and The fire intensity within the subject building is considered to beequivalenttothatofatypicalclass2building.
(iv)thefirehazard;and Thefirehazardscontainedwithinthebuildingarenodifferenttothatofatypicalclass2building.
(v)thenumberofstoreysinthebuilding; Thebuildingonlycontains4 storeyswhich is considered toensure that
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and rapid evacuation to open space can occur whilst ensuring that firefighting operations can be undertaken from outside that will mitigateagainstfirespreadtoneighbouringbuildings.
(vi)itsproximitytootherproperty;and The subject window openings are only marginally less than thatpermitted under the BCA (2.9m in lieu of 3.0m) and the provision ofmetallic fly screenswithmaximum 2mm aperture sizewill ensure thatpilotedignitioncannotoccur.
(vii) any active fire safety systemsinstalledinthebuilding;and
ThebuildingisprovidedwithsmokealarmsandfiredetectionandalarmsystemsaspertheDTSprovisionsoftheBCA.
(viii) the size of any fire compartment;and
The upper levels of the building are considered to be a single firecompartment with additional compartmentation provided around eachSOUtofurtherreducetheimpactoffirespreadwithinthebuilding.
(ix)firebrigadeintervention;and ThenearestfirebrigadeatHornsbyiswithinreasonableproximityofthebuildingandisafulltimestationthatwouldhaveeasyandquickaccesstosite.
(x)otherelementstheysupport;and Notapplicabletothisalternativesolution.(xi)theevacuationtime. The evacuation time is not considered to differ from that of a standard
class2dwelling.
3.9AssessmentConclusion
Whilst the DTS provisions of C3.2 and C3.4 require the provision of window wetting fire sprinkler protection toautomaticclosingorpermanentlyclosedwindowswithin3moftheboundaryfiresourcefeatureinabuildingofTypeAconstruction, in this instance, a qualitative and quantitative assessment has been undertakenwhich has establishedthatsprinklerprotectionisnotrequiredtobeprovidedastheseopeningsareunlikelytocausetheunduespreadoffire.On this basis, Performance Requirement CP2 is considered to be satisfied subject to the following additionalrequirements:
• Bedroomwindows1and2withinunitsG.1,1.1and2.1shallbeprovidedwithmetallicflyscreens,suitableforuse in bushfire prone areas as per the requirements of AS3959, with maximum 2mm aperture size.Alternatively,thesewindowscanbefixedintheshutposition.
• Bedroomwindows2and3,andthebathroomwindowwithinunitsG.4and1.4shallbeprovidedwithmetallicflyscreens,suitableforuseinbushfireproneareasaspertherequirementsofAS3959,withmaximum2mmaperturesize.Alternatively,thesewindowscanbefixedintheshutposition.
• Bedroom windows 1 and 2, and the bathroom window within unit 2.4 shall be provided with metallic flyscreens, suitable for use in bushfire prone areas as per the requirements of AS3959, withmaximum 2mmaperturesize.Alternatively,thesewindowscanbefixedintheshutposition.
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4.0ALTERNATIVESOLUTION2–EXTENDEDTRAVELDISTANCES
An Alternative Solution has been developed to address the proposed deviation from the DTS provisions to permitextendedtraveldistancesontheapartmentlevelsofthebuildingofupto8.8mtothesingleexitservingeachstoreyinlieuofthemaximum6mpermissibleundertheDTSprovisionsoftheBCA.
4.1Deemed-to-SatisfyDeviation
Pursuant to A.0.10(a) of BCA the following DTS provisions have been identified as being subject to the alternativesolution: D1.4Exittraveldistances(a) Class2and3buildings—
(i) Theentrancedoorwayofanysole-occupancyunitmustbenotmorethan—(A) 6mfromanexitorfromapointfromwhichtravelindifferentdirectionsto2exitsisavailable;
or(B) 20mfromasingleexitservingthestoreyatthelevelofegresstoaroadoropenspace;and
(ii) nopointonthefloorofaroomwhichisnotinasole-occupancyunitmustbemorethan20mfromanexitorfromapointatwhichtravelindifferentdirectionsto2exitsisavailable.
4.2DetailsofAlternativeSolution
InaccordancewithClauseD1.4(a)(i)(A)above,itisarequirementthateachSOUentrancedoorwaybenofurtherthan6m froman exit. In this case, thedistanceof travel to the top stair tread (considered to the exit), is at the furthest,located8.8mfromthefurthestSOUentrancedooronlevel1.Thiscanbeseeninthefigurebelow.
Figure2–ExtendedTravelDistanceonLevel1(Level2traveldistancesaresimilar)
4.3RelevantPerformanceRequirements
PursuanttoA0.10(b)ofBCAperformancerequirementsDP4andEP2.2havebeenidentifiedasbeingdirectlyrelevanttotheDTSprovisionsidentifiedinSection4.1above.DP4Exitsmustbeprovidedfromabuildingtoallowoccupantstoevacuatesafely,withtheirnumber,locationanddimensionsbeingappropriateto—(a) thetraveldistance;and
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(b) thenumber,mobilityandothercharacteristicsofoccupants;and(c) thefunctionoruseofthebuilding;and(d) theheightofthebuilding;and(e) whethertheexitisfromaboveorbelowgroundlevel.EP2.2(a) Intheeventofa fire inabuildingtheconditions inanyevacuationroutemustbemaintained fortheperiodof
timeoccupantstaketoevacuatethepartofthebuildingsothat—(i) thetemperaturewillnotendangerhumanlife;and(ii) thelevelofvisibilitywillenabletheevacuationroutetobedetermined;and(iii) theleveloftoxicitywillnotendangerhumanlife.
(b) Theperiodoftimeoccupantstaketoevacuatereferredtoin(a)mustbeappropriateto—(i) thenumber,mobilityandothercharacteristicsoftheoccupants;and(ii) thefunctionoruseofthebuilding;and(iii) thetraveldistanceandothercharacteristicsofthebuilding;and(iv) thefireload;and(v) thepotentialfireintensity;and(vi) thefirehazard;and(vii) anyactivefiresafetysystemsinstalledinthebuilding;and(viii) firebrigadeintervention.
4.4AssessmentMethodology
Inordertoaddress theprovisionsof theBCA,aquantitativeandabsoluteperformancebasedsolution formulated inaccordance with A.0.3(a)(i) and A.0.5(b)(ii) has been adopted to demonstrate the compliance of the AlternativeSolutionwiththerelevantPerformanceRequirements.
4.5AcceptanceCriteria
It must be demonstrated that in the proposed trial design incorporating extended travel distances, the proposedarrangement categorically satisfies each element of the relevant performance requirements. If this is demonstrated,compliancewithDP4andEP2.2isconsideredtobeachieved.
4.6QualitativeAssessment
BCASectionD1.3outlineswhenfireisolatedstairwaysarerequiredtobeprovided.Inaclass2buildinghavingariseinstoreysof4withthebottommoststoreyonlyusedtohousevehicles,astairwayprovidingegressforthebuildingisnotrequiredtobefireisolated.Whilstitisthereforepermittedthatthisstairwayprovidesdirectconnectionbetweenthethreeapartmentlevelsinthebuilding, in this instance the central exit interconnects the threeupper storeysof thebuildingonlyandprovidesnointerconnectiontothebasement.Furthermore,thisexitisproposedtobeprovidedwithsmokeseparatingconstructionateachlevelwiththeentrancedoorwayconfiguredasaself-closingsolidcoredoorwaywhichwillbelocatedat5.4mfromthefurthestapartmentonlevel1and5.0mfromthefurthestapartmentonlevel2.Thiscanbeseeninthefigurebelow(level2shown).Itcanbeseenthatwhilst the traveldistance technicallyexceeds themaximumpermissible6mto thesingleexit, theproposed smoke resisting construction, coupledwith the fire rated bounding construction afforded through normalapartmentconstruction,willensurethatoccupantsreachaplaceofrelativesafetyearlier.Furthermore,thelikelihoodofsmokeingressintothestairwayfromlevels1or2(wheretheextendedtraveldistancesoccur),isreducedtherebyincreasingtheabilityforoccupantstoevacuatefromthebuilding.
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Figure3–ProposedTrialDesignIncorporatingSmokeResistingConstructiononLevel2(Level1similar)
Asameasureofconservatism,topreventsmokeloggingoftheentrycorridoronthegroundfloor,itisproposedthatmediumtemperaturesmokesealsbeprovidedontheentrydoorstoapartmentsonthegroundfloorofthebuildingascanbeseeninthefigurebelow.
Figure4–ProposedTrialDesignIncorporatingSmokeSealsonGroundFloorofBuilding
On this basis, the arrangement is considered to provide a high degree of life safety and is considered to achievecompliancewith relevant performance requirements DP4 and EP2.2 subject to the assessment against the relevantperformancerequirementscontainedbelow.
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4.7AssessmentagainstrelevantPerformanceRequirement
ThefollowingisanassessmentoftherelevantPerformanceRequirementDP4andEP2.2.
DP4 Exits must be provided from a building to allow occupants to evacuate safely, with their number, location anddimensionsbeingsappropriateto-(a)thetraveldistance;and Whilstthetraveldistancetothetopofthestairwayisincreasedbeyond6m,
smokeresistingconstructionprovidedbetweenthefurthestapartmentandthe stairway,which encloses the entire staircase, provides a safe place foroccupantsbeforethe6mdistancehaselapsed.Onthisbasistheincreaseinlife safety to building occupants from the affected apartments in at leastsufficient to offset the additional 3.5s of egress time (assuming aconservativetravelspeedof0.8m/s).
(b) the number, mobility and othercharacteristicsofoccupants;and
Itisexpectedthatthemajorityofoccupantswouldberesidentswhowouldbe familiarwith the location of the exit. The building contains a relativelylownumberofbuildingoccupants and therefore evacuation is expected tooccurrapidly.
(c)thefunctionoruseofthebuilding;and
Theuse as a residential unit suggests occupantswill be very familiarwithexit options. Any guests are expected to be either accompanied, or willfollowexitsignageasappropriate.
(d)theheightofthebuilding;and
The distance of travel from the top floor to the point of discharge onlyinvolvestravellingdowntwolevelstoreachgroundfloorwheretheuseofanon-fireisolatedstairwayisconsideredtobeadequate.
(e) whether theexit is fromaboveorbelowgroundlevel.
Notrelevanttothisalternativesolution.
EP2.2 (a) Intheeventofafireinabuildingtheconditionsinanyevacuationroutemustbemaintainedfortheperiod
oftimeoccupantstaketoevacuatethepartofthebuildingsothat:
(i) the temperaturewillnotendangerhumanlife;and
Theadditionofsmokeseparationofthestairwayontheupperlevel,andtheprovisionofmedium temperature smoke seals to thedoorwayswithin thegroundfloorlobbywilldecreasetheabilityforfire/smoketoaffectbuildingoccupantsseekingevacuationfromthebuilding.
(ii)thelevelofvisibilitywillenabletheevacuation route to be determined;and(iii) the level of toxicity will notendangerhumanlife.(b)Theperiodoftimeoccupantstaketoevacuatereferredtoin(a)mustbeappropriateto(i) the number, mobility and othercharacteristicsoftheoccupants;and
Itisexpectedthatthemajorityofoccupantswouldberesidentswhowouldbe familiarwith the location of the exit. The building contains a relativelylownumberofbuildingoccupants and therefore evacuation is expected tooccurrapidly.
(ii)thefunctionoruseofthebuilding;and
Theuse as a residential unit suggests occupantswill be very familiarwithexit options. Any guests are expected to be either accompanied, or willfollowexitsignageasappropriate.
(iii) the travel distance and othercharacteristicsofthebuilding;and
Whilstthetraveldistancetothetopofthestairwayisincreasedbeyond6m,smokeresistingconstructionprovidedbetweenthefurthestapartmentandthe stairway,which encloses the entire staircase, provides a safe place for
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occupantsbeforethe6mdistancehaselapsed.Onthisbasistheincreaseinlife safety to building occupants from the affected apartments in at leastsufficient to offset the additional 3.5s of egress time (assuming aconservativetravelspeedof0.8m/s).
(iv)thefireload;and Thefireload,intensityandfirehazardisnotconsideredtodifferfromthatofatypicalapartmentbuilding.(v)thepotentialfireintensity;and
(vi)thefirehazard;and(vii) any active fire safety systemsinstalledinthebuilding;and
ThebuildingwillbeprovidedwithactivefiresafetysystemsaspertheDTSprovisionsof theBCAwhichwillconsistofsmokealarmsordetectors, firehydrantsandportablefireextinguishers.
(viii)firebrigadeintervention. The nearest fire brigade at Hornsby iswithin reasonable proximity of thebuildingandisafulltimestationthatwouldhaveeasyandquickaccesstosite.
4.8AssessmentConclusion
Theaboveassessmenthasdemonstratedthattheproposedincreasesintraveldistanceareconsideredtobesufficienttobesufficientlyoffsetthroughtheproposedtrialdesignincorporatingadditionalsmokeresistingconstructionaroundthestairwayandwithinthegroundfloorlobbyofthebuilding.On this basis, it is considered that via demonstrating equivalence with the BCA DTS provisions, the relevantperformance requirements DP4 and EP2.2 are considered to be satisfied subject to the following additionalrequirements:
• Theentrydoorwaystothestairwaysonlevels1and2shallbeconfiguredasself-closingsmokedoorswhichshallbeprovidedwithmediumtemperaturesmokeseals.Theconstructionaroundthewallsandceilingshallberesistanttothepassageofsmokethroughsealingofanypenetrationsthroughthewall/ceilingconstructionofthestairwayonthesetwoupperlevels.
• ThedoorwaysopeningintothelobbyfromtheSOUsandservicesroomonthegroundfloorshallbeprovidedwithmediumtemperaturesmokeseals.
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5.0ALTERNATIVESOLUTION3–REDUCTIONINFIRERESISTANCELEVELS
Analternativesolutionhasbeendevelopedtopermitthebathroomstocontaina30mmsetdownintheconcreteslabforthetilebedandtoassesswhetherornotthiscompromisestheabilityoftheconcreteslabtoachievetherequiredfireresistancelevelof90/90/90or120/120/120dependingonthelocationofthesetdown.
5.1Deemed-to-SatisfyNon-compliance
ThefollowingDTSprovisionshavebeenidentifiedasbeingsubjecttothealternativesolution:B1.4(b) DeterminationofstructuralresistanceofmaterialsandformsofconstructionThestructuralresistanceofmaterialsandformsofconstructionmustbedeterminedinaccordancewiththefollowing,asappropriate:(b) Concrete: (i) Concreteconstruction(includingreinforcedandprestressedconcrete):AS3600. (ii) Autoclavedaeratedconcrete:AS5146.1. (iii) Post-installedandcast-infastenings:..Further to this, Spec. C1.1 requires an FRL of 120/120/120 be achieved on the ground floor of the buildingwhichseparates the basement level carpark from the residential areas, and that an FRL of 90/90/90 is provided betweenapartmentlevels(level1and2slab).
5.2DetailsofBCADTSDeviation
Inordertoprovidetherequiredwaterproofing,whilstensuringtherequiredfallstowardsfloorwastescanbeachievedinwetareas,atypicalconstructiondetailinvolvessettingdowntheslabandscreedingthefloorontoptoenabletiledfloorswithinwetareastobeinstalledatgrade.Thistypicaldetailcanbeseeninthefigurebelow.
Figure5–ProposedSlabSetDownArrangement
Asisevident,wheretheslabissetdown,adecreaseinconcretecoveroverthesteelreinforcementexistswhichwillreduce the required fire resistance of the slab. This alternative solutionproposes to calculate the required concretecoveronthesteelelementstodeterminewhetherornot theproposed30mmreduction inthe200mmconcreteslabwillcompromisetheabilityfortheslabtoachieveanFRLof120/120/120intheworstinstance.
6.3RelevantPerformanceRequirement
PursuanttoA0.10(b)ofBCAperformancerequirementCP1andCP2havebeenidentifiedasbeingdirectlyrelevanttotheDTSprovisionsidentifiedabove.CP1andCP2statethat:
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CP1Abuildingmusthaveelementswhichwill,tothedegreenecessary,maintainstructuralstabilityduringafireappropriateto-(a) thefunctionoruseofthebuilding;and(b) thefireload;and(c) thepotentialfireintensity;and(d) thefirehazard;and(e) theheightofthebuilding;and(f) itsproximitytootherproperty;and(g) anyactivefiresafetysystemsinstalledinthebuilding;and(h) thesizeofanyfirecompartment;and(i) firebrigadeintervention;and(j) otherelementstheysupport;and(k) theevacuationtimeCP2(a)Abuildingmusthaveelementswhichwill,tothedegreenecessary,avoidthespreadoffire-
(i) toexits;and(ii) tosole-occupancyunitsandpubliccorridors;and(iii)betweenbuildings;and(iv)inabuilding
(b)Avoidanceofthespreadoffirereferredtoin(a)mustbeappropriateto-(i) thefunctionoruseofthebuilding;and(ii)thefireload;and(iii)thepotentialfireintensity;and(iv)thefirehazard;and(v) thenumberofstoreysinthebuilding;and(vi)itsproximitytootherproperty;and(vii)anyactivefiresafetysystemsinstalledinthebuilding;and(viii)thesizeofanyfirecompartment;and(ix)firebrigadeintervention;and(x) otherelementstheysupport;and(xi)theevacuationtime.
5.4AssessmentMethodology
In order to address the provisions of the BCA, a performance based approach will be adopted to demonstratecompliance of the Alternative Solution with the BCA. The proposed Alternative Solution will review the proposedsolutionusingquantitativemeasuresagainsttherequirementsofCP1andCP2.Thequantitativeanalysiswillcalculatethe required level of concrete cover over the structural elements to determine whether or not the fire resistingperformance is insufficient to achieve the required FRLs. In the case that the required FRLs are incapable of beingachieved,itisproposedtoundertakefireseveritycalculationstodeterminewhatFRLswouldberequiredinordertoovercomeaflashoverfirewithinthebuilding.
5.5AcceptanceCriteria
Itmustbeacceptedthat therequiredconcretecoveroversteelreinforcementwithinthe200mmthickconcreteslab(wherereducedto170mmdueto30mmslabsetdown)isreadilyachievabletoeitherachievetheDTSFRLsasoutlinedintheBCAorreducedFRLswhichwillbesubjecttofireseveritycalculationsifrequired.
If this can be demonstrated, it will be considered that the solution adequately satisfies the relevant performancerequirementsCP1andCP2.
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5.6QuantitativeAssessment
Research undertaken by the Portland Cement Association (Bilow et. al 2008) provides a technical review of therequiredconcreteperformancewhenexposedtofire.Thereviewoutlinestheminimumthicknessesoffloorslabs,andtheminimum required concrete cover over steel reinforcement beams in order to achieve certain durations of fireresistingperformance.Thetablebelowdeterminesthatinordertoachieveafireratingof2hours,theminimumslabthicknessisbetween3.6and5inches(91.4to127mm)dependingonthetypeofaggregateused.Inthiscasetheslabthicknessis200mm,whichisproposedtobereducedinareasby30mmtoaminimumslabthicknessof170mm.Thegroundfloorslabtherefore isconsideredtobeofsufficient thickness toachievetherequired120/120/120(2hour)fireresistingperformance,andthelevel1and2slabsaresimilarlyconsideredtoachievetherequired90/90/90(1.5hour)FRL.
Figure6–MinimumSlabThicknesstoAchieveFireResistingPerformanceinCastinPlaceFloorandRoofSlabs(ininches)
Thepaperalsooutlines theminimumrequiredconcretecoveroversteel reinforcementbeamswithinconcreteslabswhichcanbeseeninthefigurebelow.Onceagain,dependingonthetypeofaggregateused,inordertoachieveafireresistanceof2hours,therequiredconcretecovermustbebetween0.75-1inches(19.1-25.4mm).Giventhethicknessoftheslabat170mmatthepointofsetdown,itisconsideredthatthiswouldbereadilyachievablebyprocuringandinstallingchairsofthecorrectdimensionatthispointintheslab.
Figure7–MinimumConcreteCoverforFloorandRoofSlabs(ininches)
On thisbasis it is considered that compliancewith theDTSprovisionsof theBCA is readilyachievablewhichwouldthereforesatisfyrelevantperformancerequirementsCP1andCP2.
5.7AssessmentagainstrelevantPerformanceRequirement
ThefollowingtableprovidesananalysisoftheproposedarrangementagainsttherelevantPerformanceRequirementCP1andCP2todeterminewhetherornotcomplianceiscapableofbeingachieved.CP1A building must have elements which will, to the degree necessary, maintain structural stability during a fireappropriateto-(a)thefunctionoruseofthebuilding;and
Thebuildingisusedasanapartmentbuilding.
(b)thefireload;and Thefireload,intensityandfirehazardareconsistentwiththatofatypicalapartmentbuilding.(c)thepotentialfireintensity;and
(d)thefirehazard;and(e)theheightofthebuilding;and Theriseinstoreysis4whichisrelativelylowandfacilitateseaseofegress
foroccupantsandeaseofaccessforattendingfirefighters.
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CP1(f)itsproximitytootherproperty;and Notapplicabletothisalternativesolution.(g) any active fire safety systemsinstalledinthebuilding;and
ThebuildingwillbeprovidedwithactivefiresafetysystemsaspertheDTSprovisionsoftheBCAwhichwillconsistofsmokealarmsordetectors,firehydrantsandportablefireextinguishers.
(h) the size of any fire compartment;and
Theupperlevelsareconsideredtoformasingle‘firecompartment’butarefurther divided into smaller fire rated areas through the provision ofcomplyingboundingconstruction.
(i)firebrigadeintervention;and Thenearest firebrigadeatHornsby iswithinreasonableproximityof thebuildingandisafulltimestationthatwouldhaveeasyandquickaccesstosite.
(j)otherelementstheysupport;and The slab is load bearing and is considered to be able to provide therequiredperformanceundertheDTSprovisionsoftheBCA.
(k)theevacuationtime. Thetimetoevacuatethebuildingwhichhasarelativelylowriseinstoreysisnotconsideredtoexceed2hours.
CP2(a)Abuildingmusthaveelementswhichwill,tothedegreenecessary,avoidthespreadoffire-(i)toexits;and Notapplicabletothisalternativesolution.(ii)tosoleoccupancyunitsandpubliccorridors;and
Notapplicabletothisalternativesolution.
(iii)betweenbuildings;and Notapplicabletothisalternativesolution.(iv)inabuilding. Aspertheinformationprovided,theproposedfireresistancelevelsarenot
proposedtobereducedbeyondthatoftheDTSprovisionsoftheBCAwhichshouldbereadilyachievableattheslabsetdown.
(b)Avoidanceofthespreadoffirereferredtoin(a)mustbeappropriateto-(i) the function and use of thebuilding;and
RefertoCP1above.
(ii)thefireload;and RefertoCP1above.(iii)thepotentialfireintensity;and RefertoCP1above.(iv)thefirehazard;and RefertoCP1above.(v) the number of storeys in thebuilding;and
Theriseinstoreysis4whichisrelativelylowandfacilitateseaseofegressforoccupantsandeaseofaccessforattendingfirefighters.
(vi) its proximity to other property;and
RefertoCP1above.
(vii) any active fire safety systemsinstalledinthebuilding;and
RefertoCP1above.
(viii)thesizeofthefirecompartment;and
RefertoCP1above.
(ix)firebrigadeintervention;and RefertoCP1above.(x)otherelementstheysupport;and RefertoCP1above.(xi)theevacuationtime. RefertoCP1above.
5.8AssessmentConclusion
Theaboveanalysisdemonstratesthatdespitehavingasetdownof30mminareasoftheslab,therequiredFRLsarestillcapableofbeingachievedproviding:
• Theminimumslabthicknessatthepointofsetdownmustnotbelessthan150mmatanylocation.• Theminimumconcretecoveronanysteel reinforcementbars runninghorizontallywithin theslabshall
notbelessthan30mm.
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Providing the above is adhered with, compliance with the relevant performance requirements CP1 and CP2 isconsideredtobeachieved.6.0ALTERNATIVESOLUTION4–FIREHYDRANTPUMPROOM
AnalternativesolutionhasbeendevelopedtoaddresstheproposeddeviationfromtheDTSprovisions topermitthefirehydrantpumproomtobeaccessedfromastairwaywhichisnotfireisolated.
6.1Deemed-to-SatisfyNon-compliance
BCAClauseE1.3hasbeenidentifiedasbeingsubjecttothealternativesolution.E1.3Firehydrants(a) Afirehydrantsystemmustbeprovidedtoserveabuilding—
(i) havingatotalfloorareagreaterthan500m2;and(ii) whereafirebrigadeisavailabletoattendabuildingfire.
(b) Thefirehydrantsystem—(i) mustbeinstalledinaccordancewithAS2419.1,exceptaClass8electricitynetworksubstationneednot
complywithclause4.2ofAS2419.1if—(A) itcannotbeconnectedtotownmainsupply;and(B) onehourwaterstorageisprovidedforfirefighting;and
(ii) where internal fire hydrants are provided, theymust serve only the storey on which they are locatedexceptthatasole-occupancyunit—(A) inaClass2 or3buildingorClass4part of abuildingmaybe servedbya single firehydrant
locatedatthelevelofegressfromthatsole-occupancyunit;or(B) ofnotmorethan2storeysinaClass5,6,7,8or9buildingmaybeservedbyasinglefirehydrant
locatedatthelevelofegressfromthatsoleoccupancyunitprovidedthefirehydrantcanprovidecoveragetothewholeofthesole-occupancyunit.
Furthertothis,AS2419.1states:6.4.2InternalpumproomsPumproomslocatedwithinabuildingshallhave–
a) Adooropeningtoaroadoropenspace,oradooropeningtofire-isolatedpassageorstairwhichleadstoaroadoropenspace;and
b) ExceptwherethebuildingissprinklerprotectedinaccordancewithAS2118.1,enclosingwallswithanFRLnotlessthanthatprescribedbytheBCAforafirewallfortheparticularbuildingclassificationservedbythefirehydrantsystem.
6.2DetailsofBCADTSDeviation
Intheproposedarrangement,theaccesstothefirehydrantpumproomisneitherachievedfromadooropeningdirecttoroadoropenspace,norfromafire-isolatedpassage.Ascanbeseeninthefigurebelow,thefirehydrantpumproomis provided with a doorway which in turn opens into an airlock which then involves having to travel belowapproximately3mofundercoverspacebeforeleadingtoopenspace.Asthepumproomdoesnotopendirecttoopenspace,thiscorridorisrequiredtobefireisolated.Theproposalistoallowthiscorridorspacetocontinuetoopendirecttoopenspaceinlieuoffireisolatingtheentirecorridor.
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Figure8–FireHydrantPumpRoomAccess
6.3RelevantPerformanceRequirement
PursuanttoA0.10(b)ofBCAperformancerequirementEP1.3hasbeenidentifiedasbeingdirectlyrelevanttotheDTSprovisionsidentifiedabove.EP1.3Afirehydrantsystemmustbeprovidedtothedegreenecessarytofacilitatetheneedsofthefirebrigadeappropriateto—(a)fire-fightingoperations;and(b)thefloorareaofthebuilding;and(c)thefirehazard.
6.4AssessmentMethodology
InordertoaddresstheprovisionsoftheBCA,anabsoluteassessmenthasbeenadoptedwhichassessestheproposeddeviation against the provisions of relevant performance requirementEP1.3 to determinewhether categorically therequirementsaresatisfiedthroughqualitativeassessmenttechniques.AnassessmentofeachofthedeviationsabovewillbeundertakenagainsteachaspectofEP1.3.
6.5AcceptanceCriteria
TheproposedarrangementwillbeconsideredtoachievecompliancewiththerelevantperformancerequirementEP1.3iftheabsoluteandqualitativeanalysisdemonstratesthateachelementoftherelevantperformancerequirementsarecategoricallysatisfied.Furthermore,thesolutionwillneedtobedemonstratedtosuittheoperationalrequirementsofthefirebrigade.
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6.6QualitativeAssessment
AS2419.1providesguidanceforexternalpumproomsasfollows:6.4.3ExternalpumproomsPumproomsandenclosures,locatedexternaltoandwithin6mofanynon-sprinklerprotectedbuildingtheyareprotecting,shallhaveenclosingwallswithanFRLnotlessthanthatprescribedbytheBCAforafirewallfortheparticularbuildingclassificationservedbythefirehydrantsystem.Asisevident,thereareoptionstolocatethefirehydrantpumproomeitherinternaltothebuilding,orexternaltothebuilding.Theintentbehindclauses6.4.2and6.4.3appearstobe:
• Toensurethatfirefighterscaneasilyaccessthepumproomwithoutbeingsubjecttothedangerouseffectsoffire
• Toensurethatfirefighters,whenlocatedwithinthepumproom,aresafefromthedangerouseffectsoffire.Inthiscase,thefullheightmasonryconstructionsurroundingthefirehydrantpumproomwillenablethepumproomto be easily fire rated through the provision of a fire door to the fire hydrant pump room. Furthermore the wallboundingthestairwayandthebasementactsasaretainingwall(toretainthefillbeneaththestair)andwillalsobeconstructedasamasonrywall.Onthisbasisthemethodofconstructionbetweenthestairway,corridorandthecarparkappearstoberelativelyfirerated.Byprovidingaself-closingfiredoorbetweenthecarparkandthestairwaycorridor,itisconsideredthatfullfireseparationcanbeachievedinthislocation.Whilst this still does not technically complywith AS2419.1 clause 6.4.2 as the entire corridor does not form a fireisolated tunnel, thearrangement is similar to thatpermitted in clause6.4.3 forexternalpumproomswhere the firepumproomandaccesstoitisfireseparatedfromthebuildingitisprotecting.Furthertothis thereasontheproposed internal firepumproomdoesnotopendirect toopenspace(aspermitted inclause6.4.2) is that there is a small sectionof overhanging soffit (approx. 3m in length).By fire ratingbetween thecarparkandthisare,theriskofafireoccurringinthisareaisextremelylowandthearrangementcanbeconsideredtobesimilartoapumproomwhichopensdirecttoopenspace.OnthisbasisitisconsideredthattheintentofAS2419.1isachievedthroughthetrialdesignwhichcanbeseeninthefigurebelow.
Figure9–ProposedTrialDesignIncorporatingFireRatedConstruction
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Onthebasisoftheaboveit isconsideredthattherelevantperformancerequirementEP1.3issatisfiedsubjecttothefollowingassessmentagainsttheEP1.3.
6.7AssessmentagainstrelevantPerformanceRequirement
The following table summarises the proposed qualitative assessment against the relevant performance requirementEP1.3.
EP1.3 Afirehydrantsystemmustbeprovidedtothedegreenecessarytofacilitatetheneedsofthefirebrigadeappropriateto—
(a) fire-fightingoperations;and
Theproposedfireratingofthewallboundingthecarparkandthestairwaycorridorwillensurethatfirefightersareprovidedwithsafeaccesstothefirehydrantpumproomtoshutofftheautomaticallyoperatedfirehydrantpumpsetsifrequiredtofacilitatefirefightingoperations.
(b) thefloorareaofthebuilding;and
Notapplicabletothisalternativesolution.
(c)thefirehazard Thefirehazardinthestairwaycorridorislargelynon-existent.
6.8AssessmentConclusion
An alternative solutionhas beendeveloped to permit the access to the fire hydrant pump room to not be via a fireisolated corridor or direct from open space. This has been demonstrated to comply with relevant performancerequirementEP1.3,subjecttocompliancewiththetrialdesignrequirementslistedbelow:
• Thefirehydrantpumproomshallbeprovidedwith fireratedconstructionachievingaminimumFRLof120/120/120withtheentrydoorwayachievingaminimumFRLof-/120/30.
• Thewall bounding the carpark and the stairway/corridor leading to the fire isolated stairway shall beprovidedwith fire rated constructionachievingaminimumFRLof120/120/120with theexitdoorwayachievingaminimumFRLof-/120/30.
• Thefirehydrantpumpshallbeautomaticallyoperatedfromapressureswitch,flowswitchorsimilar.
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7.0CONCLUSIONS
7.1Conclusion
TheAlternative Solutionhasbeendevelopedusingaquantitative assessment andaqualitative comparisonwith theDeemed-to-Satisfy Provisions and quantitative assessment and is considered to comply with BCA PerformanceRequirementsCP1,CP2,DP4,EP1.3andEP2.2.TheBCArecognisestheseAssessmentMethodasacceptablemethodsfordeterminingthat theAlternativeSolutionsatisfies thePerformanceRequirement inaccordancewithBCAClausesA0.3(a)(i)andA0.5(b)(ii).Accordingly,basedontheabove,itisconsideredthatthedirectlyrelatedPerformanceCP1,CP2,DP4,EP1.3andEP2.2havebeenmet,providedtheAlternativeSolutionrequirementslistedaboveareimplemented.
7.2SpecificationoftheFinalTrialDesign
Considering the relevant provisions of the BCA and the above assessment, the Alternative Solution, subject to theprovisionoftheTrialDesignrequirements,isconsideredtomeetandcomplywiththePerformanceRequirementCP1,CP2, DP4, EP1.3 and EP2.2. The Trial Design requirements detailed in each solution and in the Executive SummarybecometheAlternativeSolutions.
7.3MaintenanceRequirements
Therecommendationsofthisreportmustformpartofthefiresafetycertificateandtheannualfiresafetystatementforthebuildingtoensuretherecommendationsofthisreportarecompliedwiththroughoutthebuildingoperation.
7.4RequirementsoftheAlternativesolution
The discussions undertaken have demonstrated compliance with the relevant performance requirements via theproposeddesignandinstallationofoffsetmeasures.TheoffsetmeasuresrequiredaspartofthisAlternativeSolutionarelistedintheExecutiveSummaryandmustbefullyimplementedinorderforcompliancetobeachieved.
JamesSunjaya JamesAlexanderDirector DirectorMFSE,B.Eng.(Elec.),B.Med.Sci.BPBAccreditedFireEngineerGradeC10TASRegisteredBuildingPractitioner(FireSafety,BuildingServices)VICRegisteredBuildingPractitioner(FireSafety)RegisteredProfessionalEngineerQueenslandNPERandCPEng(FireSafety,BuildingServices)
B.App.Sci(Bldg),GradDip(DispRes),ME(Firesafety),GradDip(BldgSurv)AIBSNationallyAccreditedLevel1BuildingSurveyorBPBGradeA1AccreditedCertifierandPCAFireSafetyEngineer
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8.0REFERENCES
• AustralianBuildingCodesBoard,“FireSafetyEngineeringGuidelines”,Edition2001,November2001,
Australia.
• AustralianBuildingCodesBoard,“TheBuildingCodeofAustralia”,Edition2011,May2011,Australia.
• AustralianBuildingCodesBoard,“TheGuidetotheBuildingCodeofAustralia”,Edition2007,May2007,Australia.
• IFEG(2005).InternationalFireEngineeringGuidelines2005,ABCB.
• NSWFB(2001/2002)."NSWFireBrigadeAnnualStatisticalReportTenYearReview."
• Bilow,D.N.,Kamara,M.E.,(2008)“FireandConcreteStructures”,ASCE
AppendixA–DataRelieduponintheFEB/RProcess
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CommonAbbreviationsUsedinFireEngineeringAbbreviation/Term Meaning
AFAC FireandEmergencyServiceAuthoritiesCouncil
AS AlternativeSolution
ASB AlternativeSolutionBrief - identical toFEB.ASBwillnotbeusedother than torelate thistermtotheFireEngineeringBrief.
ASR AlternativeSolutionReport-identicaltoFEB.ASRwillnotbeusedotherthantorelatethistermtotheFireEngineeringReport.BCA BuildingCodeofAustralia.
CFD ComputationalFluidDynamics–Usedtodescribethefiremodellingforabuilding
Comparative
Amethodologyusedforafireengineeringanalysisthatusesacomparisonwiththedeemedto satisfy provisions of the BCA. Thismethodology shows that the alternative solution isequivalent to the DTS provisions of the BCA and is often referred to as the equivalenceapproach.
DTS Deemed-To-Satisfy-RepresentingthedeemedtosatisfyprovisionssetoutintheBCA.
Equivalence The equivalence approach is a fire engineering approach using a comparison to the DTSprovisionsoftheBCA.FEB FireEngineeringBrief-identicaltoASB.FEBisusedthroughoutthereport.
FER FireEngineeringReport-identicaltoASR.FERisusedthroughoutthereport.
FDS Fire Dynamics Simulator – The software program used to perform fire modelling onbuildingsFRL FireResistanceLevel
FRNSW FireandRescueNewSouthWales
IFEG InternationalFireEngineeringGuidelines
NFPA NationalFireProtectionAuthority
SFPA SocietyofFireProtectionEngineers.
ClientDesignandBuildingRegulatoryObjectivesTheclientdesignobjectivesaretoaddresstheissuesofdeemed-to-satisfynon-compliancewiththeproductionofanalternativesolutionthatmeetstherelatedPerformanceRequirement.OneofthepurposesofthisFireEngineeringReportistoprovidethestakeholderswithadocumentforconsiderationandtoaddfurtherinputwithregardstothespecificobjectives.ThestructureoftheBCAisdepictedinthefollowingfigureandisahierarchaldocumentwithobjectives,functionalstatementsandPerformanceRequirement.
TheprimaryobjectivesoftheBCAaretoprotectthelifesafetyofoccupantsbyallowingthemtoexitthebuildingwithoutbeingexposedtohazardousoruntenableconditions,theprotectionofadjacentbuildingsfromcollapseorfirespreadandprotectionofthelifesafetyoffirefightersbygivingreasonabletimefortheemergencypersonneltoperformtheirduties.
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ThePerformanceRequirementaretheonlysectionoftheBCAtowhichadesignmustcomply,withobjectivesandfunctionalstatementsgivenasguidancetoexplaintheintentofthePerformanceRequirement.SatisfyingthePerformanceRequirementcanbeachievedthroughoneofthreeways:
a) ComplyingwithDeemed-To-Satisfy(DTS)provisionsoftheBCAb) FormulatinganAlternativeSolutionwhichcomplieswiththePerformanceRequirementc) Combinationofa)andb)
ForthisparticularprojectthemeansofcompliancetotheBCAwillbeshownbycomplyingtoa/b/cabove.BCAclauseA0.9providesthefollowingassessmentmethodstodeterminethatabuildingsolutioncomplieswiththeBCAPerformanceRequirement:
a) Evidence to support that the use of amaterial, form of construction or designmeets a Performance Requirement or aDeemed-to-SatisfyProvision
b) VerificationMethodssuchas—i) TheverificationmethodsintheBCA;orii) Such other verification methods as the appropriate authority accepts for determining compliance with the
PerformanceRequirementc) ComparisonwiththeDeemed-to-SatisfyProvisionsd) ExpertJudgement
TheassessmentmethodsthatwillbeadoptedforthisprojectareinaccordancewithA0.9aboveandthespecificmethodsaredetailedinthealternativesolutionsections.
MethodsofAnalysisThemethodsofanalysisusedinthedevelopmentofalternativesolutionsaredetailedinBCAClauseA0.9,andincludeA0.9(b)(i) VerificationMethods,suchastheVerificationmethodsintheBCAA0.9(b)(ii) VerificationMethods,otherthanthoseintheBCAthattheappropriateauthorityacceptsforcompliancewiththe
PerformanceRequirementA0.9(c) Comparisontothedeemed-to-satisfyprovisionsoftheBCAA0.9(d) ExpertjudgementInordertosatisfyBCAClauseA0.5-MeetingthePerformanceRequirement(b) formulatinganAlternativeSolutionwhich-
(i) complieswiththePerformanceRequirement;or(ii) isshowntobeatleastequivalenttotheDeemed-to-SatisfyProvisions;
Thespecificassessmentmethodsusedfortheanalysisaredetailedinalternativesolutionsectionforeachissue.
RelevantIFEGSub-SystemsTherelevantIFEGsub-systems(SS)forthisanalysisare:
IFEGSub-System Description Symbol
Sub-systemA
FireInitiationandDevelopmentandControl
Limitationofignitionsources
Limitationofnatureandquantityoffuel
Arrangementandconfigurationoffuel
Separationofignitionsourcesandfuel
Management of combustibles including housekeepingmeasures
Electricalsafetyequipment
Regularplantmaintenance
Adherencetoproceduresfor'hotwork'(e.g.welding)
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IFEGSub-System Description Symbol
Sub-systemB
SmokeDevelopmentandSpreadandControl
Smokebarriers
Naturalsmokeventing
Mechanicalsmokemanagement
Sub-systemC
FireSpreadandImpactandControl
Separationoffuel
Separationofbuildings
Fireresistivebarriers
Fireresistivestructuralelements
Fireresistiveair-handlingducts
Fireresistivedampers
Exposureprotection
Sub-systemD
FireDetection,WarningandSuppression
Automaticandmanualdetectionequipment
Automaticandmanualwarningequipment
Surveillanceequipment
Automaticsuppressionequipment
Manualsuppressionequipment
Sub-systemE
OccupantEvacuationandControl
Evacuationplans
Occupanttraining
Emergencycommunications
Egresssignage
Egressroutes(includingfireisolatedelements)
Sub-systemF
FireServicesIntervention
Type of fire services available (full-time/permanent orvolunteer).
Characteristicsoffireservicescapabilityandresources
Fireserviceaccesstothesiteandtothebuilding
Watersuppliesandinfrastructure
AcceptanceCriteriaandFactorsofSafetyfortheAnalysisQualitativeAssessmentsTheacceptancecriteriaforqualitativeassessmentsaretheequivalencetoadeemedtosatisfysolution(preferred)orthecollectiveagreementofthestakeholders.TheIFEGallowsbothqualitativeandquantitativeapproachesandstatesthat-"themethodschosenwillbeappropriatetotheapproachused".TheIFEGstates-"Intheminorityofcases,qualitativeanalysismaybeagreedduringtheFEBprocesstobesufficientfortheconsiderationofasinglenon-complianceissue.Thebasis(logic)onwhichthisapproachisusedshouldbedocumentedwithappropriatereferences.A“Delphi”approachmayalsobeappropriateincertaincircumstances,whereagroupofsuitablyqualifiedexpertprofessionalsreachconsensusagreementregardingthesuitabilityofaparticularsolution."TheIFEGfurtherstates-"Bothcomparativeandabsoluteapproachesmaybeadoptedintheanalysisstrategy.Themethodschosenwillbeappropriatetotheapproachused.Comparativeapproach:
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Typically,thefiresafetyprovidedbyoneelement,orasub-system,orthecompletefiresafetysystem,iscomparedtotheleveloffiresafetythatwouldbeachievedinanidenticalbuildinginwhichthatelement,sub-systemorsystemisdesignedincompliancewiththedeemed-to-satisfyorprescriptiveprovisionsidentifiedinSection1.2.8.Iftheanalysisiscarriedoutonsuchacomparativebasis,itwillinvolvethesameassumptions,models,calculationsandinputdatafortheproposedtrialdesignandthedeemed-to-satisfyorprescriptivedesign.Acomparativeapproachaimstodeterminewhetherthealternativesolutionisequivalentto(orbetterthan)thedeemed-to-satisfyorprescriptivedesign.Thecomparativeapproachisoftenreferredtoasan“equivalence”approach."QuantitativeAssessmentsThefollowingacceptancecriteriaareproposedfortheassessmentofthealternativesolutionscompliancewiththePerformanceRequirementoftheBCA.Theacceptancecriteriawillbetodemonstratethatfiresafetyisnotadverselyaffectedandthattheoccupantsmaysafelyevacuatethebuildingand/orthefirewillnotspreadtoadjacentpropertyand/orwillallowfirefighterstosafelyperformtheirduties.HeatRadiation-Thelimitingconditionforradiationisassumedtobeintherange1.57to6.3kW/m2.Thetolerancetimeforradiationatthislevelis6minutes.
FireBrigadeIntervention:Inconsideringtheroleofthefirebrigadeinattackingafire,itisimportanttoestimatethetimeatwhichthebrigadewillbeeffectiveinlimitingthespreadofthefireandreducingtheheatoutputofthefireintheenclosureoffireorigin.Howeverthisresponsetimeisvariableandisafunctionofthetimeatwhichthealarmisreceivedatthefirestation,thetraveltimetothebuilding,thesetting-uptimeoncethefirebrigadehasarrivedandthetimetoimpactthefire.Whilethefirebrigadewillbeavailabletoassistevacuationthroughsearchandrescueofoccupants,thisactionisnotrelieduponforoccupantevacuation.Thefiresafetyassessmentisthereforeconservativeinthisregard.Theconditionsthatdefinethetenabilitycriteriaforfirebrigadepersonnelwillbeconsiderediftheoccupantscannotbeshowntohavesufficientavailableegresstimepriortoonsetofuntenableconditions.Incertaininstancesthefirebrigadeinterventiontimeswillberequiredtobedeterminedandtenabilityforthefirefightersassessedi.e.deletionofsprinklersfromacarpark.ThetimeforthefirebrigadetoarriveandcommencefirefightingoperationswillbedeterminedusingtheFireBrigadeInterventionModelorliteraturedataonthefirebrigaderesponsetimetofires.SummaryofTenabilityFailureCriteria:
Condition CriteriaConvectiveheat Temperature>60oCwhensmokelayerisbelowtenabilityheight.Radiantheatexposure
2.5kW/m2 at head height or smoke layer temperature exceeds 200oC when abovetenabilityheightof2.1m.
Visibility 10mwhen smoke layer is below tenability height of 2.1m for large rooms or 5m forsmallrooms.
Toxicity OD>0.1m–1(10dB/m)whensmoke layer isbelowtenabilityheightof2.1m,butnotaccessedifvisiblyacceptable.
Thefollowingtableisanoverviewofthetenability’sasacceptedbytheFireandEmergencyServiceAuthoritiesCouncil(AFAC)1.
RoutineConditionHazardousCondition
ExtremeCondition
CriticalCondition
MaximumTime,min 25 10 1 10
1 Weng Poh ‘Tenability in building fires: Limits and design criteria’. Fire Australia, 2010, No. 3,. pp 24-26
T<1.57kW/m2to6.3kW/m2
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ApproachesandMethodsofAnalysisApproachFireengineeringdesigncaninvolvetheuseofanumberofapproachesincluding:
• ComparativeorAbsolute• QualitativeorQuantitative• DeterministicorProbabilistic
TheIFEGgivesdescriptionsofeachtypeofapproach,whereitcanbenotedthatadeterministicorprobabilisticapproachcanonlybeappliedtoaquantitativeanalysis.Thedifferencesbetweenacomparativeandabsoluteapproachandtypicalexamplesofacceptancecriteriaaredepictedinthefollowingtable(reproducedfromUKFireEngineeringGuidelinesPD7974-0).Comparativevs.AbsoluteApproach
FireSafetyObjectives
AnalysisMethod Deterministic Probabilistic
Comparative TimeavailableforescapeisatleastequaltothatinanequivalentcodecompliantbuildingLevelofriskoflifeequivalenttoacodecompliantbuilding
Absolute ThetimeavailableforescapeexceedsthetimetountenableconditionsExpectednumberofcasualtiesperyear
Adefinitionofeachtypeofapproachisoutlinedinthefollowingtable,whichhasbeenadoptedfromtheIFEG.Thetypeofapproachadoptedwilldependonthetypeofcomplianceissueinquestionandsubsequentmethodsofanalysiswillbeprepared.AnalysisApproaches
Approach Definition
Comparative A comparative approachaims todeterminewhether the alternative solution is equivalent to (orbetterthan)thedeemed-to-satisfyorprescriptivedesign.Thecomparativeapproach isoftenreferredtoasan“equivalence”approach.
Absolute In an absolute approach, results of the analysis are matched directly against the PerformanceRequirementoftheBCA,usingagreedacceptancecriteria.
Qualitative AqualitativeanalysismaybeagreedduringtheFEBprocesstobesufficientfortheconsiderationofminorstand-alonecompliance issues.Thebasis (logic)onwhich thisapproach isusedshouldbedocumentedwithappropriatereferences.
Quantitative Thecomplexityofthecomplianceissueswilloftenrequireaquantitativeapproach.ThisentailstheuseofoneormoreofthemanyanalysismethodsavailableThequantitativemethodswilloftenbesupportedbyadditionalqualitativearguments.
Deterministic Deterministicanalysesarebasedonphysicalrelationshipsderivedfromscientifictheoriesandempiricalresults.Characteristically,foragivensetofinitialboundaryconditions,adeterministicmethodologywillalwaysproducethesameoutcome.Theydonot,however,indicatetheprobabilityofthatoutcomebeingrealized.
Probabilistic Probabilistic approaches use a variety of risk based methodologies. These methods generally assignreliabilities to the performance of the various fire protection measures and assign frequencies ofoccurrenceofevents.Theymayanalyseandcombineseveraldifferentscenariosaspartofacompletefireengineeringevaluationofabuildingdesign.Thisuseofmultiplescenariosandtheircombinationthroughprobabilistictechniquesisthekeyfeatureofsomeofthemethods.
ConstructionandCommissioningRequirementsThefiresafetymeasuresshallbedesigned,installedandcommissionedinaccordancewiththerelevantAustralianStandards.
• Themanagementof thebuildingmustbeawareof theAlternativeSolutioncontainedwithin thebuilding,aswellas therequiredmeasuresformaintenance.
• The BuildingManagement System,must incorporatemaintenancemeasures to ensure satisfactorymaintenance, testingandinspectionofallfiresafetymeasures.
Allfiresafetymeasuresaretobecommissionedandtestedpriortooccupationofthebuilding.Thefireservicescontractormustprovidecertificationoftheinstallationandcommissioningofthefireservicesrequiredbythisreport,includingbutnotlimitedto:
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• FireHydrantsSystems• Smokedetection• Firedoorsandsmokeseals• Exitsignage&emergencylighting• Appropriatedoorhardwareanddoorswing
Thefiresafetymeasureswithinthebuildingmustbemaintainedtoensurecorrectoperationatalltimesthatthebuildingisoccupied.Allfirefightingequipmentshouldbetaggedwhentested/inspectedandlogbookskeptup-to-dateforallsmokedetection,warningsystemsandsprinklersystems(whereinstalled).AnannualfiresafetycertificatemustbesubmittedtothelocalconsentauthorityandtheNSWFireBrigadeeachyearindicatingsatisfactoryperformanceofthefiresafetymeasurescontainedwithinthebuilding.Theannualfiresafetystatementshouldbedisplayedinaprominentplacewithinthebuilding(i.e.themainentryfoyer).Thecorrectoperationandmaintenanceofthebuildingsfiresafetymeasuresiscriticalinaffordinganadequateleveloffiresafety.OtherissuesidentifiedintheFEB/Rthatwillneedtobeincorporatedintothemanagementinuseofthefacilityinclude:
• Nosmokingpolicyistobeimplementedinallpublicareas.• Commissioning and integrated function testing of all fire safety and protection systems including interfaces to ensure
properfunction.• AllessentialservicesaretobemaintainedandtestedinaccordancewithBCAandAustralianStandardAS1851.• Ensureexitsandpathsoftraveltoexitsremainunobstructed(inparticularstairways).• Avoidstorageofmaterialsinunoccupiedareas.• Limitstorageofflammable/combustiblematerialstodesignatedandapprovedareas.• Preventchockingopenfire/smokedoors.• Preventstorageofmaterialsthatcouldhinderaccesstofirefightingequipment.