Towards zero life cycle GHG emissions apartment buildings in Lebanon

Abstract

Buildings are one of the main drivers of greenhouse gas (GHG) emissions and their life cycle emissions need to be significantly reduced in order to address the unprecedented climate emergency. While there are numerous studies on zero operational energy and GHG emissions buildings, very few studies exist on buildings that aim to reach zero life cycle GHG emissions buildings. The apartment building typology is particularly challenging due to the very small roof area per apartment and the limited capacity for renewable energy generation. This study investigates a four-storey apartment building in Sehaileh, Lebanon and modifies it to reach zero life cycle GHG emissions through a series of measures targeting embodied and/or operational GHG emissions. Both a life cycle GHG emissions analysis and a life cycle cost analysis are conducted on all measures their combination, including the installation of a 50kWp photovoltaic array for the building. Results demonstrate that it is possible to achieve zero life cycle GHG emissions for that building typology and number of storeys, in a Lebanese Mediterranean climate, but at a net life cycle cost of ∼43 kUSD2020 over 50 years, compared to the base case guilding. Implications in terms of policy and further research are discussed.