Materials and service lives alterations impacts on reducing the whole life embodied carbon of buildings: A case study of a student accommodation development in Ireland

To meet the growing demand for student accommodations and fulfil climate change targets, it is essential to establish a methodology for evaluating and reducing their whole-life embodied carbon (WLEC) emissions. The study aims to develop a robust methodology for assessing and reducing the WLEC emissions of a new student accommodation development in Ireland as a replicable case study for other countries. The developed method is based on EN 15978 building whole life cycle standard and EU Level(s) framework. The reduction methodology based on hotspot analysis identifies the most impactful life cycle modules and materials. WLEC assessments were performed on an actual project with two base case scenarios: blockwork (BW) walls for the tender stage and precast walls (PC) for the as-built stage. The WLEC emissions were 749 kgCO 2 e/m 2 for the BW and 838 kgCO 2 e/m 2 for the PC. The production stage modules (A1-A3) and the replacement module (B4) were the primary contributors, with 56% and 34%, respectively. The proposed WLEC reduction methodology altered the concrete and the rebar with lower EC alternatives available in the Irish market. It modified the service life of seven building elements to align with the manufacturer's standards. Consequently, the WBEC emissions were reduced by 27% and 33% for the BW and PC scenarios. This methodology promotes low-EC and durable alternatives to replace conventional materials for the upcoming student accommodation projects in Ireland to achieve the Climate Action Plan EC reduction target by 2030. • A robust methodology is developed for evaluating and reducing the WLEC of student accommodation buildings in Ireland. • The WLEC of the precast concrete walls design is higher than the blockwork walls tender design by 12% due to the increase in the use of reinforced concrete. • Low-carbon concrete and rebar can reduce the WLEC of the student accommodation developments by 18%. • Materials with a 50 years’ service life can reduce the WLEC of student accommodation developments by 23%. • The blockwork wall scenario which incorporates low-carbon concrete and rebar with durable materials, gets the lowest WLEC by 28% less than the base case.