Whatmakesabuildingproductsustainable?

Thecomponentsoftheproductarepredominantlyrenewableresources,theproductisdurableanditisrecyclableatendoflife.

Ithaslowembodiedenergyi.e.theenergyconsumptioninmanufactureandtransportandthewastegeneratedinmanufactureisrelativelylow.

Theeffectsofinstallationandusearepositiveonhumanhealthandtheenvironmentduringthelifeoftheproduct.

Theproductiseconomicallyviabletoproduce

Preferablyconsumerswithanaverageincomecanaffordit

GrowinglowTHCfibrehemp therenewableresource Hardy,cansurviveheavyweatherbutnotanywaterlogging needs1/3ofthewaterfor

lucernetobeviable preferssandyloambutcangrowinmostsoilsotherthanclay

Bioremediator takesupheavymetalsandexcessnutriente.g.goodbuffercropnearriparianzones.

Hempfibrefarming(plantedatmin40Kgperha)canmakeasignificantcontributiontoaddressinglegacycarbon.Itsfastgrowingbiomasshasahighcarbonuptakeinaveryshortperiodoftime.

Taprootandstubblefromsustainableharvestingincreasessoilcarbon

OnceasoilcarbonmethodologyisdevelopedforbroadindustryapplicationhempwillbeeligibleforcarbontradingintheKyoto,nonKyotoandvoluntarymarkets.

Excellentcropinrotation,improvessoilhealthforsubsequentcrops stubbleandleafcontributesignificantamountsofnitrogenbecauseofthedensityofplanting(especiallyhempfibre).

Hempfibrevariety,AshfordNSW2010.

FormoreinformationseeLandlineTheHempComebackwww.northernrivershemp.org

IndustrialhempjustpriortoharvestingatAshford2010

ThehemphurdproductusedinbuildingProcessingiswithahammermill theoutsidebastfibreisseparatedoutasarethefinesandthedust.Allbutthedustisusableandthisiscompostable.

Growingandprocessingfibrehempregionallythechallenges

Hempisquiteeasytogrowandharvest quitelabourintensivetoprocessonalargescale.Thiscouldbeviewedaspotentialemploymentin theagriculturalsector.

Shortageofsuitablereadilyavailableseed

Farmersneedtoshareexistingharvestingequipmentandtogainefficiencies,therewillbetobeinvestmentinmachinery.Canadaisproducingmodernmachinery wedontneedtoreinventthewheel.

Processingforbuildingmaterialscanandshouldberegionalbut requiressomeenergytosetupandsomemoderateinvestment.

Thereisaneedforinvestmentinanotherhempmanufacturingindustrypreferablyusingthebastfibre,intheregionornearby,fortheindustrytomaximiseitspotential.

OpportunitiesfortheNRRegion

Emergingindustrygloballyasthefeedstockformultipleindustries Hugegrowthpotentialforfarmersbecauseofthemanyproductsthatcan

bemade.SeveralhavebeenidentifiedasbeingsuitableforAustralianinvestmentandmanufacture

TwosignificantemergingmarketsdemandinghempfibreinAustralia. Thereisademandforsustainablygrownhempandaneedforconsumers

todemandit,evenifittakesawhile.

Enormousopportunityforregionalcarbonharvestingandpreferablylockingitintocarbonsinkssuchashouses/buildings.

HousingisresponsibleforalargepercentageoftheAustraliasandeveryotherwesterncountriescarbonfootprint.Wecouldstarttoreversethat.

HempConstruction thepotential

AdnamsBreweryHailedasGreenestWarehouseinBritain

2400sqmBreweryandDistributionCentre

Overhangingeavesandabufferspaceateachwarehouseentrancehelpmaintainambienttemperaturesinsideandpreventexcessiveheatgainsorlossofcoldfromthewarehousearea.Infact,Adnams,thefirstcommercialbuildingintheU.K.tobebuiltusinglimehemp,requiresnorefrigerationunitsatall aremarkablefeatforabeercompany.Allrefrigerationisaccomplishedviathenaturalpropertiesofthestructureitself.

TheTriangleSwindonKevinMcLeod

TheTriangle,a42homedevelopment,isthefirstschemebyHabOakus,thejointventurebetweenKevinMcCloudsdevelopmentcompany,Hab,andhousinggroupGreenSquare.

Theschemeconsistsoftwoandtwoandahalfstoreyterracescontainingtwo,three,andfourbedroomhomesaroundacentralvillagegreen.Theeastandwestterracesarebothterminatedbythreestoreycornerblocks,eachcontainingthreeapartments,providingfocalpointsasyouenterandleavethesite

Timberframeconstructionwithhemplimewalls.

BuildingcommerciallyThePanMixerProducesbetween45cubicmetresofmixperdaytosupportacrewof4tobuildthewallsofatwostoreystudioin10days.

ThelocalproductandAustralianhomes

Twostoreystudio,KynetonVictoria

Billen Cliffs, Northern Rivers

Pole structure, Mountaintop, Northern Rivers

CulburraBeachhouse,

EurobodallaShire

RetrofittingforenergyefficiencyCawongla,NorthernRivers Unlinedweatherboardhome

insulatedwithhemplime

Whatistheleastsustainablepartofhempbuilding?

Thebinderismadefromminedproductsincludinglime.(Someproductmanufacturersusesandtoreplacesomeofthelimebinder.)

Allmanufacturersofhemplimeproductsaddsomethingtotheirproductstotriggersettingandtostabilisehydratedlime.Theseareeitherpozzolans,cements,byproductslikeflyash,hydrauliclimesornaturallyoccurringcements,oramixture.Percentagesinwallingvaryworldwidefrom50% 14%.

Quantityofadditivesvariesdependentonapplication.

Ifhempwhichisahighvolume,lightweightproductistransportedlargedistances,thecarbonfootprintassociatedwithtransportstartstoerodethecarbonneutrality oftheproduct.

Whatissustainableabouthempconstruction?

Hempbuildingslockuplargevolumesofhemp fibrecontentvariesbetweenproductsandbetweenmanufacturers

Hempmasonrycanbeusedforwalls(50 65%byvolume,roofinginsulation(80%fibrebyvolume)andfloors(50%),fornewbuildsandretrofits

Thebuildingmaterialcuresthroughcarbonationi.e.Itdrawscarbondioxidefromtheatmosphere,harvestingfurthercarbonoveranextendedperiodoftime

Itislighttoworkwith,doesnotrequireahighskillleveljustcarefulbuilding Thematerialisveryforgiving itcuresslowly canbeusedforupto6hours

exceptinextremeheat drymaterialcanbereusedatarateof10%insubsequentbatches.Thereislesswasteinthebuildingprocess. Anywastecangoonthegarden.

Hempmasonrybuildingsdonotgrowmoulds Hempmasonrywallsbreathe thishasaprofoundeffectonthermal

performance

Whatelse?

Hempmasonryprovidesthermalmass Monolithichempconstructioncreatesanairtightbuilding. Hempmasonrybuildingsdonotoffgasthetoxiccombinationofgases

releasedbymanycurrentlystillcommonlyuseddomesticandcommercialconstruction

Thematerialdoesnotburn Insectsandrodentsdonotlikethematerial Ithashighflexuralstrength Itisdurableasaremostbuildingsconstructedwithlime. Thereisa300yearoldNationalTrusthemphouseinJapan

Thermalinsulationandthermalinertiainhemplimebuildings

Thethermalperformanceofbuildingisacomplextoassess.

Despiteheatspreadsinthreedifferentways(conduction,convectionandradiation),buildingregulationsconcentrateonheatlossbyconductivity.

TheUvalue,alimitprescribedbytheregulations,measurestheheat flowthrough1m2ofwall,floororrooffor1Cdifferenceintemperaturebetweenitssides(LimeTechnology,2006).Thehigheritistheloweristheinsulationperformance.

Uvaluesarecalculatedassumingthatthematerialsareinasteadystate,(wheretemperaturesonbothinternalandexternalsurfacesdonotchangeoveraperiodoftime).Inreality,humansoccupybuildings,ambienttemperaturesfluctuate,andthereforethewallsofabuildingarepermanentlyinadynamicsituation.

Uvaluecalculationsdonottakeintoaccounteitherthetimeortheenergytakenformaterialstoheatupandcooldown.

AccordingtotheresultsoftheHaverhilltestbyBRE(2002)the Uvalueofthehemplimebiocompositebuildingwashigherthanthatmeasuredinthestandardmasonrybuilding.Howevertheinternaltemperatureinthelimehempstructuretendedtobe2Chigherthanthestandardbuilding,regardlessofhavingthesamefuelconsumptionfortheperiod.IthasthereforebeenarguedthattheUvalueisnotapropermethodtoassessthethermalperformanceoflimehemp(Prof.TomWoolley,2006,QueensUniversity,Belfast).

HempLime Strawbale Brickveneer Pise/mudbrickThermalperformance Excellent

Rvalue2.75Uvalue0.360.37W/m2KSeebelow

Excellent Notasgood Highthermalmass,slowtoheatupandslowtocooldown

Constructioncost =BrickVeneer(BV) Lowest BVbenchmark MoreexpensivethanBV

Workability,easeofconstruction

Lightandeasytoworkwith,relativelyfastwithrightequipment,easytobuild

Simpleandquick,somewhatspecialised

Requiresseveralskilledtradestoconstruct

Veryheavytoworkwith

Vermin Verminproof,termiteproof Verminariskiftheygetintothewalls,termitescaneatoutstrawbalefromtheinside.

Verminexcludedwith[properdetails)

Termitesborestraightthrough

Fireproof Innatelyfireproofandprotectswalltimbers

Fireratingdependsonthicknessofrender

Externallyfireproof Externallyfireproof

Embodiedenergy LowEE LowEE HighEE LowEECarbonfootprint Absorbsupto10tcarbonperha

duringcropcycleandabsorbsfurthercarbonasawall

Absorbscarbonasacrop Highfootprintforkilnfiredbricks

Neutral,especiallyifsourcedonsite

Damprot RotresistantasHemplimemasonrymineralises.

Corecanrotoutifwatergainsaccess

Dampproof Dampproofnessreliesonroofoverhang

Recycling Canbefullyrecycled,simplybreakdown,mixwithnewbindermaterialandreconstruct,oruseasamulch

Unlikelytobereused,canbeusedasmulch

Brickscanbecrushedandrecycled,relativelyhighcostprocess

Dusttodust

Soishempbuildingenergyefficient? .thetheoreticalperformanceofthehemphousesdoesnotmatchtheirperformanceinreallifeinthat

theyareusingsignificantlylessenergythanpredicted.BREClientreport209177Rev1(2002)

Initialresultsseemedtoshowthatalthoughtherewasapproximatelythesameenergyconsumptionfordomesticheatinginboththelimehempandconventionalmasonryhouses,theinternaltemperatureofthehemphouseswasmaintainedat1or2Chigherthanthebrickhouses.

SecondreportbyBRE(2003)consistingofathermographicinspectionfoundthatthelimehempbuildingexternaltemperaturewasabout5Clowerthanthestandardmasonrybuilding.

Hemplimeeliminatesanyformofthermalbridgingbycompletelyisolatingthesupportingwoodenstructure.

Monolithichemplimeconstructionisairtightavoidinganylossofheatfromtheinside.

Thermalinertiaistheabilityofamaterialtostorecalorificenergyandtoreleaseitoveralongerperiodoftime.Limehemphasanabilitytocontroldifferencesintemperatureandthereforetohelpmakebuildingsmorecomfortable.

Thetwofollowinggraphsshowthetemperatureandhumiditylevelsinanemptyhemphouseandanemptybrickhouseon7thJanuary2003.Inbothhouses,theheatingwas switchedoninthemorning(between6.30amand9.00am),andagainintheevening(between4.30pmand 10.30pm).

In the hemp house, the desired temperature of 21 C is reached after the heating has been on for around 2 hours, and is then thermostatically maintained at that level for the remainder of the heating period. In the brick house, however, a maximum temperature of 20 C is only reached after the heating has been on for approximately 4 hours.Therefore, in the morning, when the heating is on for a shorter period of time, the desired temperature is never reached in the brick house. (Centre for Alternative Technology, Wales)

When the biocomposite is exposed to the sun it warms up very little, and when the outside temperature drops it is able to release heat to balance the difference in temperature between the inside and outside. (Perier 2001) These properties were also confirmed by the BRE s tests (2001) in Haverhill.

Research in 2009 (Coulston) at the Centre for Alternative Technology (CAT) in Wales that thermal mass plays an important part when considering heat loss in all building constructions, and that a combination of the unique properties of hemp and lime, in a dynamic situation, might outperform other materials in terms of energy efficiency.The research also leads to the conclusion that the government should beextremely cautious when insisting on compliance with building regulations, since U-values ratings may be flawed.

Experimentalprojects:AustraliasfirstEarthship,AgnesWatersQueensland

January2012

FormoreinformationonNSWhemplicensing,farmingandourregionalhempindustry:www.northernrivershemp.org

Formoreinformationon:AustralianhemplimebuildingmaterialsHempmaterialsresearchattheAustralianCentreforConstructionInnovationUNSWInformationonbuildingwithhempanddesigningforhempandcompliancewithBCAandlocalcouncilrequirements

AustralianHempMasonryCompanywww.hempmasonry.comContact:KlaraMarosszeky0422750612