How green building certificates fulfill the environmental goals in the buildings’ life cycle

Abstract

While buildings are responsible for the consumption of nearly 40% of the total energy usage anda large amount of material, they are considered as one of the potential solutions for climate change mitigation. The emissions caused by energy and material use are produced during the life cycle of buildings including pre-use and use stages as the main ones followed by end of life (EoL) stage.The consideration of sustainability and the concern regarding limited natural resources has brought about in the preparation of green building certificates during the last three decades. Among different green building certificates, Building Research Establishment Environmental Assessment Method (BREEAM) is the most widely used while Leadership in Energy and Environmental Design (LEED) is most internationally adopted.

This dissertation is going to evaluate green building certificates regarding their fulfillment of reduction in energy and material use via LEED as a reference. Two main stages of pre-use and use are considered while the EoL stage is ignored because of its low contribution. The dissertation is based on four journal articles, and a mixture of qualitative and quantitative methods including literature review, case studies, and statistical data analysis has been used.

It was found that, in the use stage, green building certificates have fulfilled the goal of decreasing energy use and emission cut especially at higher levels of certificates but at lower levels the decline in energy consumption is questionable. Regarding the pre-use stage, green building certificates have poorly allocated the points to the materials that have lower environmental impacts like wood.The scenarios of different material selection confirm the lower environmental impacts of wooden buildings based on life-cycle assessment (LCA) as a sustainability evaluation method meaning that it is noteworthy to put more emphasis on material selection in green building certificates. Wooden buildings construction as a recommended solution not only yield fewer emissions during their production compared to concrete and steel ones but also have a significant potential of storing carbon.

The study shows that the future environmental plans and regulations by policymakers need continuous updates and modifications in order to find the best solution for climate change mitigation in different locations and times, this applies to green building certificates as well. While the body of research in green buildings has mainly focused on the use stage, there needs to be more attention on the pre-use stage. Besides the motivation for the production of future energy from renewable and clean sources, the embodied emissions which occur in a short time play a significant role in climate change mitigation.