Sustainability implications of service life on residential buildings - An application of life cycle sustainability assessment framework

Sustainable building design should consider durability, affordability, resource conservation, intra and inter-generational social equity aspects, and stakeholder's perspective throughout its service life. This research has applied life cycle sustainability assessment (LCSA) framework to estimate the sustainability performance in terms of a single score, and to identify avenues for sustainability improvement strategies of buildings. These case study buildings were modeled by taking into account the variation in building materials while maintaining architectural designs, covered area and location constant. The paper demonstrate the flexibility of this LCSA framework as all indicators are interlinked and any change or improvement in one or some indicators affects others positively and negatively. The sustainability objectives were assessed on an annual basis to capture the implications of the variation in the service life of buildings. Buildings made of recycled steel-framed roof, brick walls, and green concrete used in slab footing, showed higher sustainability performance among case study buildings. The use stage energy consumption and maintenance activities have been identified as the main hotspot. The cleaner production strategies (CPS) including product modification (double glazed window) and technology modification (rooftop solar photovoltaic panels, solar water heaters) were thus deemed appropriate to further reduce the use stage triple bottom line (TBL) impacts. These CPS have improved the sustainability performance of the case study buildings by 30-49%. The LCSA analysis confirms that the service life of buildings and their components have a significant bearing on the overall sustainability performance of residential buildings. However, the material selection at the design phase is crucial to building sustainability performance due to its durability and thermal properties. The longer service life of the building could result in more sustainable buildings only if service life of the non-structural components is aligned with service life of building to mitigate the maintenance activities.