Scenario analysis of embodied energy and CO2 emissions for multistory apartments in Indonesia

Abstract

Contribution in the building sector to the global warming can be tackled by diminishing greenhouse gas (GHG) emissions (mainly CO2) not only from operational energy but also from the embodied energy (EE) of construction materials. Harvested Wood Products (HWP) such as Cross Laminated Timber (CLT), Glued Laminated (Glulam) timber, among others, make multistorey wooden buildings possible. These wooden buildings could help to reduce EE and CO2 emissions significantly. A material flow analysis (MFA) using an I-O (Input-Output) table was used to compare three scenarios for an 8-story apartment building in Indonesia (total floor area: 9140 m2): First, the building had a reinforced concrete structure. Second, the building had a “hybrid” structure with reinforced concrete cores and first-floor elements, consisting of CLT floor panels, and Glulam columns and beams. Third, the building used only CLT panels besides reinforced concrete cores. The results showed that the last scenario achieved the largest CO2 emissions and embodied energy reductions (58 t-CO2 and 905 GJ), compared with the first scenario (81 t-CO2 and 1110 GJ). Furthermore, we compare two methods to apply displacement factors (DF) to assess the CO2 emissions savings for each CO2 ton in wood products substituted in place of non-wooden products between the three building scenarios.