A life cycle assessment of low-energy residential multistory mass-timber buildings in central Chile

The lifecycle assessment (LCA) of low energy residential mass-timber (MT) building is evaluated. The MT building design features improved thermal envelope design (e.g. increased thermal insulation, glazing and airtight sealing). Lifecycle environmental impacts are assessed using SimaPRO 9.0 and building thermal performance is evaluated using TAS 9.5. Global warming potential for MT building and reinforced concrete (RC) building designs were estimated as 97.4 and 162.8 kg of CO2 eq per square meter, respectively. Recognizing wood materials as a carbon sink, the usage of mass-timber products achieved a negative net of 310,000 kg of CO2 eq/building. Operational emissions from domestic space-conditioning were reduced significantly by 288.6 kg of CO2e (83%) per square meter, over 50-year useful life using MT constructions rather than conventional RC. Consequently, mass-timber construction shows a higher potential than conventional RC to reduce carbon emissions of multi-story buildings located in Santiago, Chile.