The overlooked criteria in green building certification system: Embodied energy and thermal insulation on non-residential building with a case study in Malaysia

• Published in: Energy (Oxford) Vol. 259; p. 124912
• Main Authors: Ng, Wai Lam, Chin, Min Yee, Zhou, Jinqin, Woon, Kok Sin, Ching, Ann Ying
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.11.2022
• Subjects: Building material; Green rating tool; Insulation envelope; Life cycle energy assessment; Operational energy; Building material; Green rating tool; Insulation envelope; Life cycle energy assessment; Operational energy
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2022.124912

A green building certification system (GBCS) is essential for sustainable city development. However, the building's embodied energy (EE) and thermal insulation have often been overlooked in GBCSs. The correlation of thermal insulation envelopes to EE and operational energy (OE) has also yet to be extensively investigated. This study adopts life cycle energy assessment methodology to evaluate the EE and OE of non-green and green-rated non-residential buildings with hotspot analysis and analyse the trade-offs between EE production and OE saving for five types of insulation envelopes. Taking Malaysia as a reference, results show EE holds 16–19% of total energy in non-green and green-rated non-residential buildings; hence EE should not be neglected in GBCS. The material consumption phase incurs half a quarter of the total EE, indicating that major recycled and low-embodied building materials (e.g., recycled steel and green cement) should be rewarded with higher points in GBCS. Insulated building envelopes save 84–87% of cooling demand than non-insulated walls, with cellulose fibre insulators consuming the least EE. It is hoped that this study can provide evidence-based outcomes to policymakers when formulating the proportion of EE and OE, and integrating insulation envelopes in GBCS to enhance energy savings further. [Display omitted] •The embodied energy of the green-certified non-residential building is assessed.•The contribution of embodied energy is 16–19% of the total life cycle energy.•Material and maintenance phases contribute 95.2–97.2% of embodied energy.•Cellulose insulator incurs the least (i.e., 230 MJ/m2) embodied energy.•Embodied energy and thermal insulation should be emphasised in green rating tools.