1. 1
November 2016
Green Square
An evidence-based policy brief: high density livings impacton climate change
The Green Square Renewal Area is a redevelopment plan informed by the City
of Sydney which seeks to transform Alexandria, Zetland, Waterloo and
Beaconsfield with sustainable design and approaches. Overall, the aim of this
policy brief supported by relevant evidence, is to assess the effect that high
density living has on climate change. The integral aspects which will inform this
brief directly correlate to the Infrastructure and Strategy Plan whereby
redevelopment will consist of mitigation and adaptation techniques to
decrease adverse effects that city living can pose on the climate.
The brief herein is for the City of Sydney and the Sydney Local Health District.
Policy recommendations will be provided through-out as to what the best
methodologies in mitigating environmental distress caused by high density
living is.
2. 2
TABLE OF CONTENTS
EXECUTIVE SUMMARY 3
The Problem 3
Policy Options 3
Policy Recommendations 4
REVIEW OF EVIDENCE 5
Background 5
Methods 5
Sydney’s Coastal Environment 6
The Urban Heat Island Effect 6
Urban Green Space 7
Ventilation (External and Internal) 7
Public Transportation 8
Healthy Equity 8
Discussion 10
IMPLICATIONS FORINCORPORATIONINTO INFRASTRUCTUREAND STRATEGY
PLAN 11
APPENDIX 13
REFERENCES 19
3. 3
EXECUTIVE SUMMARY
The Problem:
It isan irrefutable factthatthe Earth’s climate is fluctuatingdue tohumanactivities.These changes
include increasedtemperaturesonlandand inoceansresultinginthe meltingof polarice caps
whichinherently raisessealevels. The aforementionedisimportantbecauseSydneyislocatedina
coastal zone putting itan increasedriskforextreme weathereventsrelatedtosealevel rise (NSW
has experiencedsealevel rise by2.1 millimetresperyear) andflooding.Extremeheateventsare
alsolikelytoincrease as a directresultof climate change. Thiswould contribute toheatrelated
illnessanddeath,increasedmosquito-bornediseases,food-borne disease andincreasedair
pollution.
There are several tacticswhichcanmitigate adverse climatechange impactstoprotectthe healthof
Australians,one of which isthe properdesignof humansettlements likeGreenSquare.Evidence
revealsthathighdensityenvironments have the potentialtomitigate climatechange eventsif built
withpropersustainable constructiondesigns.
Policy Options:
Economicincentives anddisincentives incorporatedintobuildingstandardswill likelyencourage
businesses,homeownersandcontractors toincorporate sustainable approachesintodesignplans.
Beloware policyoptions:
Market Based: These wouldinclude cap-and-tradeschemeswhichplace acap on the permitted
level of emissions,creditschemeswhichgrantcreditstothose whoreduce overall emissionsbeyond
baseline andcarbon taxeswhichcreatestax structuresrelatingtogreenhouse gasemissions.
Regulatory Programs: Incorporationof energystandardsintothe designof buildings.
Subsidisationor Grant Programs: The NSW or Commonwealthgovernmentcouldsubsidise
contractors,businessesandhome ownerswhenbuildingsare builtwithsustainabilityinmind.
ReportingRequirements:Thiswouldinclude minimumenergyefficiencyrequirementsand the
disclosure of energyratingsystems wherebybuildingswouldbe ratedbasedoff energy
performance.
4. 4
Policy Recommendations:
A cumulative approachislikelytobe mosteffectivewhencreatingsustainabledesignpoliciesand
beloware recommendations:
PolicyOption 1: Statutory Enforcementof NSW Environmental Policy BuildingSustainabilityIndex;
BASIX 2004
Require developerstosubmitdesignplanswhichmeetthe State Environmental PlanningPolicy
(SEPP) guidelinesbyimplementingacarbontax or cap-and-trade schemes therebylimiting
greenhouse gasemissions.
PolicyOption 2: Non-StatutoryEnforcementof GreenStar Tools Program
Demonstrate compliance with sustainabledevelopmentstrategies,thiswouldinclude:improving
indoorair quality, decreasingenergy use,increasingpublictransport, reusingwater, employing
environmentallysustainable materials, efficientlyusingland, andincorporatingurbangreenspace.
PolicyOption 3: Financial IncentivesforImplementationofSustainable Construction Designs
Thiswouldinclude rebatesforuse of specificmaterialsinconstructiondesigns(solarpanels,water
systemsand cooling/heatingsystems),grantsprovidedtoschoolsandtowns to incorporate
renewable energyuse,andwaivingplanningpermitfeeswhenthere isdemonstratedcommitment
towardsenvironmental efficiency.
5. 5
REVIEW OF EVIDENCE
Background
Scientistshave longgrappledwiththe ideathathumans,mostlyin developedcountries,are
negativelyimpactingthe earth’sclimate throughvariouslifestyle factors.Thistensionisfurther
exacerbatedwitharapidlyincreasingworldpopulation.Therefore,toease ourcarbon footprint,
newbodiesof evidence withregard toadaptationandmitigationstrategiesinourbuiltenvironment
are arising[1].While there is no“one size fitsall”approachto ease climate change impactsinbuilt
environmentswithdifferentgeographicalcontexts,there isevidence tosupportthathighdensity
livingdesigns,if done withproperconstructiontechniques,are more sustainable thanlow density
livingdwellings.
The synthesisof scientificevidence below reveals the primaryareasof concernwithregardto high
densitylivinganditsimpactonthe environment. Further, the evidence seekstoreveal the best-
practice methodologies foroverallconstructiontechniquestoinformsustainable approachestoease
climate change impacts [2]. Effective sustainabledesignisdependentupongeographical location,
i.e.Sydneyisconsideredahumid,subtropical environmentanditsweatherishighlyinfluencedby
the ocean.Therefore, evidence whichsupported constructiondesigns inclimatescomparable to
Sydneywere givenmore cloutthanthose of drasticallydifferentenvironments.
The overall purpose of thisreview isto informbestpractice methodologiestomitigate climate
change throughsustainable development.GreenSquare shouldbe plannedwithattentionpaidnot
onlyto Sydney’sclimatebut,alsotoconstructiontechniqueswhichmaximise healthpromotion
principles bydecreasingcarbonfootprint impactsthroughsustainabledesigns.
Methods:
The researchquestionswhichIattemptedtoanswerthroughasystematicsearchon Scopus were:Is
highdensitylivingsustainableandwhatare the bestapproaches tomitigate highdensityliving’s
impacton climate change?Next,Idevelopedfivekeywordsearchestoproperlyencapsulatethe
evidence base;theseincludedhighdensitylivingANDclimatechange (144 results,18 relevant),high
densitylivingANDurbanheatislands(14results,7 relevant),highdensitylivingANDventilation(37
results,6 relevant),highdensitylivingANDgreenspace (39results,13 relevant) andhighdensity
livingANDtransportation(151results,19 relevant).Ialsosearcheddatabasestobetterinformmy
research,these included:Cityof Sydney(GreenSquare),GreenBuildingCouncil Australia(GreenStar
Rating),SustainableCitiesCollective(UrbanDensityandSustainability), IPCC,SmartGrowthOnline
6. 6
and International DistrictEnergyAssociation.Iexcludedliteraturewhichhadaprimarilytheoretical
focus,studieswhichfocusedonwildlife(trees,birds,insects,andcoral reefs),studieswhichdidnot
focuson builtenvironmenttechniquestomitigate climate change inhighdensitylivingandstudies
whichhad a primarilymedical focus.Therefore,case studiesproducedinNew York,HongKong,
Torontoand Melbourne were valuable inthissearchtoilluminate the evidence base onadaptation
and mitigationstrategies.Lastly,Ididnotlimitmyresearchto a specifictimeframe;some evidence
was outdatedtherefore,studieswere excluded.Ionlysearchedliterature inEnglishandIdidnot
limitmyfocusto any geographical location;howeversome studiesweremore relevantthanother
basedoff climate settings.
Sydney’s CoastalEnvironment
Sydneyissusceptible tothe urbanheatislandeffectanddroughtsinhotsummermonths.Inthe
wintermonths,stormsurgeswhichhave the abilitytoproduce floodsbasedon Sydney’s close
proximitytothe ocean are of concern [3, 4]. GreenSquare,more specifically,islocatedinaflood
plaintherefore floodmitigationtechniquesare pivotal tothe overall constructiondesignplan.In
2005 the NSW governmentprovidedapolicyaspart of the FloodplainDevelopmentManual 2005
withoverall aimstoreduce lossintimesof flooding.Planningispivotal inenvironmentswhichare
susceptibletofloodingandincorporated intothe designplansisa2.5 km stormwater drain[3, 4].
Further,there are plansto redevelopexistingdrainage systemswhichfall inthe GreenSquare flood
plain.The designplansseekstoefficientlyrecycle waterwherebyexcessstormwaterrunoff will be
recycledforhumanconsumption. The incorporationof urbangreenspace alsodecreasesflooding
effects;howeveramore exhaustivesolutiontodealingwithfloodingshouldbe consideredwhen
constructiontakesplace ina knownfloodplain [5].
The Urban Heat Island Effect
GiventhatSydneyisalreadysusceptible tothe urbanheatislandeffectfromageographical
perspective,sustainableplanningwhichreduceshighdensitylivingsimpactonurbanheatislandsis
pivotal.Researchshowsthat,whilehigh densitylivingdoesundoubtedlyproduce more heatthan
lowerdensityareas,if designplansincorporate the sustainable designof roofs,roadways,walkways
and vegetationthenthe heateffectwillsubstantiallydecrease [6,10].Simplyput,usingthe albedo
technique (alsoknownasreflective coatings)whendesigning buildings effectivelyreduces the urban
heatislandeffect.Evidence suggeststhe incorporationof white roofsandgreenroofswillmitigate
overall greenhouse gaseffectswhile alsoremaining costeffective;recommendationsforspecific
roof designsare shownbelow:
7. 7
Low SlopedRoofs: Use single-plymembranes,built-uproofs,bitumensheetmembranes,
spray polyurethane foamroofs;
SteepSlopedRoofs: Use shinglesand/ortiles;
Low and SteepSlopedRoofs:Use metal and/orgreenroofs[11-14].
Hot and humidclimates,like Sydney,will needtopayclose attentiontothe overproductionof algae
and mouldongreenroofs [13]. Next,roadwaysandwalkwaysare correlatedtothe urbanheat
islandeffectwhendarkermaterialssuchasasphaltare used.Therefore,white cementfixtures are
suggestedtodecrease heatoutput.Further,effectivewaystodecrease heatisthe incorporationof
urban greenspace intodesignplans [9,14].
Urban Green Space
The incorporationof urbangreenspace such as parks,trees,shrubs,grassand flowershave a
significanteffectoncoolinghighdensity livingenvironments [5].The additionof urbangreenspace
not onlyeasesclimate change impactsbutalsomaximisespublichealthprinciplesthroughstressand
violence reduction;further,physical activityratesincreasetherebydecreasingobesityrates [15].
Simplyput, the implementation of greenspace ispivotaltomaximisingsustainable practicesbecause
it regulatesmicroclimatesandbiophysical processesthroughthe absorptionof excesscarbon
emissions [16].Urbangreenspace coolsenvironmentsthroughshade production while also
mitigatingstormwaterrunoff issues [4].
Ventilation (External and Internal)
The incorporationof sustainable internal andexternal ventilationsystemscanmitigate climate
change impactsin highdensitysettings.Implementationof natural ventilationtechniquesare
preferredtoairconditioningandheatingsystemsince theyproduce highcarbonemissions;i.e.
implementationof windows,patios,brickandwoodinconstructionplans canreduce carbon
emissionsbykeepingpremisescoolerinsummermonths [17].Intrinsically,highdensitypremises
are notexposedtonatural lightingaseffectivelyaslow densitypremises.Therefore,the
incorporationof districtcoolingandheatingsystemsare necessary,especiallyintropical andhumid
climatessuchas Sydney [18].Three notable advancednatural ventilationstrategiesare:
Cross Ventilation;
Stack Ventilation;
Single-SidedVentilation[20].
8. 8
The incorporationof these systemswill maximise publichealthprinciplesbyensuringthatthermal
comfortis met;essentially,inhotsummer monthsitispivotal tohave propersystemswhich
mitigate overheating inolderpopulations [19].The managementof these systemsintermsof proper
duct cleaningispivotal whenensuringthatpopulationhealthisnotthwartedasthese systemshave
the potential tocreate pathwaysforharmful pathogengrowths;anexample of thisitthe SARS
outbreakthattook place inHong Kong [17-20].
The properalignmentof buildings candecrease windstagnationtherebycoolinghighdensity
environmentsandthisinturn will maximise publichealthprinciples.Incorporationof the Air
VentilationAssessmentSystemsinahotand humidclimate like Sydneyisencouraged.Thisincludes:
Breezeways/airpaths: prevailingwindsshouldtravelwithbreezeways;
Buildinglayout: buildingmorphology withalignmentof buildingheightsintorows will move
air aroundmore efficiently;
Buildingdisposition:heightarrangementshoulddecrease withthe directionof the
prevailingwindsandtall buildingsshouldbe spacedoutproperlyasto not blocknatural air
flow(alsoknownasstreetgridorientation);
Buildingpermeability:gaps/voidsinbuildingconstructionatthe pedestrianlevelwill
increase airflowtherebydecreasingheatdiscomfort [21,22].
The ultimate concernwithhighdensitylivingandexternal ventilationisairquality.Building
orientationwhichdecreaseswindstagnationwill improve the thermalcomfortforpedestriansand
more effectivelycool highdensityenvironments [21,22].
Public Transportation
Highdensitylivingcandecrease overall carbonemissionswhencitiesare properlyplannedaround
publictransitsystems [23-26].A mainconcernwhendealingwithhighdensitylivingistraffic
congestiontherefore,if citiesare plannedefficiently aroundtransitsystems thenvehicle miles
travelledwill decrease.Compactdesignalsoencourages increasedwalkingandbikingforcivilians
whichfurthermaximisespublichealthprinciples.The cityof Sydneyveryefficientlyemployspublic
transitsystemsthroughthe incorporationof the lightrail,trainandbussystemsand GreenSquare
has beendesigned withincorporationof all the above principles [4,32].
Healthy Equity
WhenconductingHealthImpactAssessmentsitisimportanttoensure thathealthequityprinciples
are incorporated.Ultimately,scientificevidence generallyprovesthatthose of lowersocio-economic
9. 9
statuswill be more negativelyimpactedbyextreme weathereventsdue toclimate change [27-30].
Generally,thisisbecause theyreside insociallydisadvantagedareaswhich were notdevelopedwith
sustainabilityprinciplesinmind. Therefore,while the sustainable designsystemsmentionedabove
can decrease adverse climate change effects andincrease health, if theyonlyappeal tothose of
highersocio-economicstatus (SES),thendesignplansshouldevolvetofita range of people from
multiple SESbackgrounds.
Table 1: Analysisof HealthEquity Data fromABS Censusof Population Housing 2006-2011
EquityAnalysis forGreen
Square
Percentagesbasedon Census
of Population andHousing
Age Structure
18-24 18.7%
25-34 37.5%
35-49 22.9%
Travel Methods
Train 12.8%
Bus 22.1%
Car-as Driver 35.5%
Weekly Individual Income
None 13.6%
$1,000-2,000 or more 50.4%
Weekly Household Income
$1500-2,999 40%
The table above isa brief synopsisof relevantcensusinformationprovidedinthe GreenSquare
Urban Renewal AreaProfileanditsrelationtoclimate change [31].First,extreme weatherevents
are more likelytoaffectolder populations more negativelythanyoungerpeople;the dataabove
revealsthe prominentage structureswhichwill reside inGreenSquare whereby37.5% of people will
be aged 25-34. Second,transportationdirectly correlateswith climatechange therefore,analysisof
data withregardto peoplesmain travel methodsrevealthatthe highestpercentagesof people
travel bytrain,bus and car. Third,weeklyincomesonanindividualandjointlevel isimportantwhen
discussingequity;overall,13.6%people have noincome and50.4% make $1,000 a weekor more.
50.4% of people residinginGreenSquare have jointincome levelsof $1,500 to $2,999. The 13.6% of
people withnoincome are likelyfull-timestudents.Overall,thisdataseekstoexpose inequities with
specificattention paidtoclimate change.The majorityof inhabitantsare youngerandtherefore
10. 10
more apt to deal withextreme weatherchangesthanolderpeople.70.4% of inhabitantshave access
to a car, trainor bus; increasingthe numberof peopletravelingbytrainand buswill decrease
climate change impacts.Lastly,the datashows that generallypeopleresiding inGreenSquare are of
higherSES and therefore, constructionplans andcostsshouldappeal tothose fromall ranges of SES;
not justhigherSES.
Discussion
The evidence above revealsthathighdensityliving,if done with properadaptionandmitigation
constructionpractices, canhave a protective effectonclimate change [33,34]. However,the
scientificliteraturehassome notable limitations:studiesdonotaddresswhatthe ideal size for
compact/highdensitylivingisandstudiesneedtospecificallyaddress certaingeographical areas
(coastal,dry,land-locked,tropical,temperatezones)withregardtomostefficientsustainable
constructiondesigns.Overall,there isageneral lackof systematicreviewsonwhatthe “best”
designsare andfurtherresearchto succinctlybringthe science andideastogetherisneeded.
11. 11
IMPLICATIONS FOR INCORPORATION INTO
INFRASTRUCTURE AND STRATEGYPLAN
The Draft GreenSquare Infrastructure StrategyandPlancomprehensivelyoutlinesstrategies which
seek toguide sustainable developmentinthe GreenSquare UrbanRenewal Area[4].Thissection
will outlinethe strategiesoffered inthe designplans andextrapolate onrecommendationsto
improve sustainability.
1: Does the infrastructure planuse frameworks and regulationtechniques to mitigatethe effect
that highdensitylivinghas onclimate change?
Sustainable developmentisacknowledged however,incorporationof sustainable construction
designsare voluntarilyproposed[pg.60].The State Environmental PlanningPolicy(BASIXSEPP) lies
the foundationforresidential developmentstoachieve minimumsustainabledevelopment
standards.The planseekstoexceedrecommendationsprovidedbythe BASIXSEPPprogram byusing
the EcologicallySustainable Development(ESD) frameworkbut,the overall limitationliesinthe fact
that there isno statutoryregulationwhichmandatesdeveloperstobuildwithsustainabilityinmind.
Recommendation:Require thatdevelopersandcontractorsnotonlyuse the BASIXSEPPand
ESD standardsbut, incorporate acarbon tax structure associatedwith excessemissions.
2: Does the infrastructure plan offer sustainabledesignmethodsforcontractors?
The plan discussesthe City’sDecentralisedEnergyMasterPlan,Tri-generation2010-2030, which
encouragesthe use of “lowcarbon electricity,hotwatertoheat buildingsandchilledwatertocool
buildings”[pg.61].There are recommendationsforsolarphotovoltaicpanelstoincrease energy
efficiencyandprivate wireswhichwill reduce networkchargestherebyincreasingefficiency[pg.61].
There are alsoplansforDecentralisedWaterMasterPlans,WaterSensitive UrbanDesign,Reducing
Mains WaterDemandand ImprovingStormwaterQuality [pg.62-65].
Recommendation:Incorporate furthersustainable designmethodsforcontractorstouse.
Thiswouldinclude the incorporationof sustainable roof designs,indoorandoutdoor
ventilationsystems andthe incorporationof AirVentilationAssessmentSystems[these
optionsare discussedonpg.7 and8 herein].
3. Does the infrastructure planofferincentives to contractors for the incorporation ofsustainable
designplans?
There isno evidence of thisinthe designplans.
12. 12
Recommendation:Waive planningpermitfeeswhensustainable designplansare submitted.
Recommendation:Encourage developerstoemploythe GreenStarRatingtool methodology
and provide subsidiesandrebatestodeveloperswhichuse sustainable methodologies.
Recommendation:Providegrantstotownshipstoadaptor mitigate climate change through
the use of sustainable designs.
Recommendation:Offerincentivestopeople whouse publictransportsystemsas opposed
to usingautomobiles.Thisrecommendationisfoundedonthe claimthattrafficcongestion
contributesasignificantamounttogreenhousegasemissions.
13. 13
APPENDIX
Table 1: High DensityLiving and Climate Change
HDL and climate
change effect
categories
Results/ Strengths Study type and
Limitations
References
Coastal Environments Sydneyresidesina
coastal plainthereby
makingitmore
susceptibletosea
level rise/excess
rainfall asclimate
change worsens.
Incorporationof urban
greenspace such as
grass and treeswhich
can absorb excess
runoff can ease
climate change
effects.
Strengths:Advice as
to howto used
sustainable urban
drainage “swales,
infiltration,detention,
and retentionponds
inparks”.
Case study:Greater
Manchester
(population of 2.5
million)whichoffered
a great range of
environmental
characteristics;
especiallyinrelation
to livingnearbodies
of water.Surface
runoff model.
Regional space
strategies,local
development
frameworks.
Limitations:Runoff in
highdensitylivingwill
still be at least65
percenthigherthan
low densityregardless
of greenspace
implementation.
Greenspace alone is
not as effective if not
usedinconjunction
withthe surface
runoff model.
Gill etal.
(2007)
Urban Heat Island
Effect
Urban area has a
greatertemperature
(.25 Celsius) thanthe
countryside (.08
Celsius).
Strengths:Highlights
healthinequityfor
those whocan/cannot
affordair ventilation
systems. Adverse
effectsonelderly
populations.
Ecological time series
analysis:HongKong
(urban) observatory
1947 to 2005 and
contrastedwithTa
KwuLing andLau Fau
Shan (countryside)
1989-2005.
Limitations:Evidence
to supportan urban
heatislandeffectwith
no evidence astohow
to do that.
Lam, C.Y. (2010)
14. 14
Lowerdensity
dwellingsemitted
greaterheatthan high
densitydwellings.
Overall,thisresearch
challenges
speculationsthathigh
densitylivingemits
greaterheat.
Strengths:Creationof
methodologyto
measure landuse and
heatproduction.
Efficientuse of landin
termsof greenspace
can reduce heatisland
effects.
Ecological:Atlanta,
Georgiametropolitan
Limitations: The heat
islandeffectdiffers
basedon ecological
environments.
Stone etal. (2001)
Extrapolationon
urban morphological
designsandoverall
the positive and
negative side effects
of highdensityliving.
Strengths:Foundthat
usingdistrict
ventilationsystems,
vertical zoningand
multifunctional and
multi-level clusters
can be more efficient.
Emphasisonthe
educationof low
energybuildings.
Case Study:Hong
Kong
Limitations:There is
no “right”way to
create low energy
buildingstodecrease
urban heatisland
effect.
Hui etal (2001)
Emphasison
mitigationstrategies:
rooftops,roadways,
parkinglots,
vegetationaswell as
examplesof
mitigationinitiatives.
Strengths:Effective
and statistically
significantwaysto
reduce urbanheat
islandeffect
Meta-analysis:Heat
islandmitigation
processes
Limitations:Cost-
benefitanalysisasper
whatis suitable for
each environmentwill
differintermsof what
the bestwaysto adapt
or mitigate the heat
islandeffectsare for
that geographical
region.
Sailoretal (2006)
Cost savings
structuresindirect
Ecological:
Sacramento,Florida,
Rosenfeldetal.(1995)
15. 15
relationtocool
surfacesandshade
treesprogram.
Strengths:Policysteps
to implement(p263)
the above to mitigate
heatislandeffect.
White SandsNational
Monument,New
Mexico
Limitations:Standards
for new construction
of buildingsare not
universal andcoststo
environmentand
monetarysavingsare
case dependent.
Urban GreenSpace Greenspace and its
abilitytodecrease
urban heatislands,
flooding,reduce
energyconsumption.
Strengths:
Developmentof
questionsand
frameworksasto
informpolicy
processes(ecosystem
services,driversof
change,greenspace
pressures,social
processes,goalsof
provision).
Delphi Technique:
Multidisciplinary
approach/discussion
to urban greenspace
incorporation.
Limitations:Lackof
understandingasto
whatthe bestwayto
plan/design/manage
urban greenspace is.
Greenspace
functionalityis
geographicallyand
sociallycomplex.
Jamesetal. (2009)
Incorporationof
vegetationcan
decrease climate
change effectscaused
by highdensityliving.
Strengths:Surface
area of tree cover,
buildingheight
impactsthe overall
successof urban
greenspace.
ParametricCase Study
usingENVI-met:33
simulationsbasedin
Hong Kong
Limitations:Not
effectiveincooling
pedestrian
environments,
building-height-to-
street-widthratios
and vertical greening
techniquesneedtobe
studied.
Ng etal. (2012)
External Ventilation Buildingdesignandits
importance on
external ventilation in
highdensityliving.
Strengths:
Recommendationsof
streetgridorientation
Computational
ParametricStudy
Mong Ok inHong
Kong:Thermal
Comfortassessments
throughPhysiological
Equivalent
Temperature
Yuan etal. (2012)
16. 16
(arrangedalongthe
prevailingwinds),
windpermeability
(buildingdistances),
air passagesclose to
ground.
Limitations:Only
considersthe wind
environmentinan
urban settings,also
scope islimitedwith
regardto building
dispositionand
variousheights.
Specifiedandsuccinct
culminationof
efficientventilation
systems:Breezeways,
Podiumcoverage,
buildingdisposition,
buildingheights,
buildingpermeability
to increase
ventilation.
Strengths:
Developmentof the
AirVentilation
Assessmentandpolicy
recommendations
Meta-Analysis:Air
Ventilation
AssessmentinHong
Kong
Limitations:
Geographyspecific
Ng etat (2006)
Internal Ventilation Focuson hospital
ward natural
ventilationsystems
while also
extrapolatingon
evidence tosupport
natural ventilations
effectondecreasing
carbon emissions.
Strengths:
Developmentof stack
ventilationsystem:
Edge in Centre out,
Edge in Edge out,
Centre inEdge out
and Centre inCentre
out (Fig1).
Case Study:UK
locationssingle sided
ventilationandedge
inand out natural
ventilation
Limitations:Night
time ventilation
control
Lomas etal. (2009)
Transportation Automobileusage is
the largest
contributingfactorto
GHG emissions;lower
inhighdensity
dwellingsdue to
decreasedneedfor
automobile use.
Case Study:Toronto
comparisonbetween
highdensityandlow
densitydwellings.Life-
Cycle Assessment
used.
Normanet al.(2006)
17. 17
Strengths:Evidence to
showthat policies
whichreduce
automotive
transportation,
increase publictransit.
Limitations:Traffic
congestionandmore
researchdedicatedto
life cycle analysis to
examine the overall
policyimplications
withregardto high
densityvlow density
living.
Transportation
accounts for28% of
GHG emissionsinU.S.
Strength:Vehicle
milestravelled;
therefore shorter
travel will reduce GHG
emissions.
Review of practicesto
minimise climate
change impacts(LEED
U.S. GreenBuilding
CouncilsLeadershipin
Energyand
Environmental Design
ratingsystems).
Limitations:Cost-
benefitanalysisof
GHG emissionsand
the builtenvironment.
Youngeretal. (2008)
Importance of
planningcities
effectivelytoincrease
publictransituse;i.e.
higherdensitycities
are typically more
efficient.
Strengths:Downward
trendwith32 cities
showingthatas
densitiesincrease
transportenergy
decreases.
Case Studies:Analysis
of UK built
environment;urban
formimplications.
Limitations:Overall
techniquesindesign
plansand effective
coordinationbetween
all stakeholdersto
informpolicy
effectively.
Steemersetal.(2003)
DecreasedGHG
emissionswith
compact
development.
Strengths:Policy
recommendationsfor
reduction intransport
sector;compact
developmentis
SystematicReview:
Urban Development,
travel andemissions
fromautomobilesin
US.
Limitations:Travel
emissionreductionis
not enoughtoreduce
GHG alone.
Ewingetal. (2007)
