b'Technical Article SectionHead:TechnicalArticle Head:RoofReplacements Deck:Theimpactonenergyandcarbonemissions Byline:JustinKoscher Word count: 2605Roof Replacements The impact on energy and carbon emissions By Justin KoscherExisting building stock can be addressed with cost-effective strategies to mitigate climate change.W iththeaimofloweringclimatechange.Afterall,oftheoverwhelm a buildings heating andtors combined with building typeswithsecondaryliteraturere-greenhousegases(GHGs)existingbuildingstockinCana- cooling systems, and escalate build- andcity-specificweatherdatatosearchonincrementalmaterial by 40 to 45 per cent by 2030da, about 70 per cent is expecteding utility expenses as well. estimate the following impacts andand labour capital costs to pro-andachievingnet-zeroemissionsbyto still be in use in 2050. 2WhileInsuchscenarios,retrofittingbenefits across Canada: duce life-cycle economic metrics 2050, Canada is transitioning towardthe structures may remain stand- buildingcomponentswithhigh-EnergyImpactsBuildingover a 30-year timeframe. acleangrowtheconomy.Tomeeting through the years, the rapidlyperformance insulation to maintainenergy models were developedWithrespecttothestudied30-these sustainability targets, Canadianchangingclimaticconditions,in- stablethermaltemperaturescanto represent the baseline andyeartimeframe,anecdotalevidence policymakersareturningtheircreasing requirements for energy- increasetheenergyefficiencyofainterventionorcode-con- suggeststheaverageservicelifeof attentiontothebuiltenvironment.efficientbuildingenvelopesandbuilding.Goingonestepfurther,gruentscenarios. 7 Bothsetsa roof system is between 20 and 40 As the countrys third-largest carbonevolving building codes can requireroofreplacementsareoneoftheofmodelsweresimulatedtoyears.Variousfactorscaninfluence emissionsource(responsibleforbuilding improvements. mostcommonandeffectiveenve- produceestimatesofwhole- thelifespanofaroof,andsystems morethan18percentofnationalSince many of the structures inlope retrofits 5for existing buildingsbuilding energy use, and theirmay be rehabilitated or recovered to carbon emissions), 1the building andCanadasexistingbuildingstockdue to the relative size of the build- energy use was subtracted topreserve the function of existing com-constructionindustryholdsmuchwerebuiltbeforethewidespreading component. produceincrementalener- ponents. At the end of its service life, potential for change. adoption of modern building ener- gysavings. a typical roof system is removed and gy codes, many of them are under- Achieving Energy Efficiency EmissionsImpactsEmis- replaced with a new roof system, in- Retrofits Hold the Key toinsulated. This is concerning as theThrough Roof Replacements sionsimpactsweredevelopedcluding insulation. The 30-year time-country is already experiencing thedirectlyfromenergysavings Climate-Adaptive Buildingimpacts of a changing climate. 3 The Polyisocyanurate Insulationas the product of energy sav- frame used in this study was selected Envelopes To further illustrate the sever- Manufacturers Association (PIMA)ings by fuel type and its corre- asanaverage,conservativeestimate Whilenewconstructioncaneas- ity of the situation, consider morecommissioned a third-party-facilitat- spondingnational-levelemis- for roof system and component ser-ilyaccommodatemodernenergy- than 85 per cent of building sec- ed study 6to quantify the benefits ofsions factor. vice life for all building types studied.efficiencytechnologyandadheretotoremissionscomefromspaceenergy-code-congruent roof replace-Economic BenefitsEnergy the latest building codes, the existingandwaterheating,aswellasthements,intermsoflifetimeenergybenefits (or cost savings) wereProof in Resultsbuilding stock can also be addressedextra energy required to heat andandcarbonemissions.Thestudycalculated as the product of en- The detailed analysis evaluates en-withcost-effectivestrategiestothecoolbuildingswithinsufficientconsideredgeneration-weightedergy savings by fuel type and itsergy savings through code-compliant aggressiveenergysavingsandemis- envelopeperformance. 4 Theel- national-levelenergycommoditycorrespondingnational-levelroof upgrades (during roof replace-sion reductions necessary to mitigateevatedenergyconsumptioncanprices, escalations and emissions fac- fuel price, 8and then combinedment) in commercial structures with 20ONTARIO ROOFING NEWSISSUE 2 2024 THE ONLY SOURCE FOR PROFESSIONAL ICI ROOFING CONTRACTORS IN ONTARIO ORN'