Analysing carbon impacts of green roof at Hilton Watford: life-cycle assessment approach

This paper investigates the environmental aspects and energy impacts of implementing a green roof system at the Hilton Watford hotel, utilising building information modelling software (Revit) for three-dimensional modelling and Insight for energy simulation. Following EN 15804:2012+A2:2019, the study employs life-cycle assessment methodology, focusing on embodied and operational carbon. Environmental Product Declarations, Inventory of Carbon and Energy database and the Royal Institution of Chartered Surveyors guideline inform embodied carbon calculations. The results show the green roof system releases 263 839.56 kgCO₂e as embodied carbon, while its sedum layer sequesters 211 468.12 kgCO₂e over a 50 year lifespan. Energy efficiency analysis indicates a 3.3 kWh/(m²/year) reduction in energy consumption, leading to a 112 130.31 kgCO₂e reduction in operational carbon dioxide emissions, highlighting the environmental benefits of green roof adoption. The findings suggest a 0.35% mitigation of whole life-cycle carbon dioxide emissions, with greater impact in situations of lower insulation effectiveness, showcasing the potential of green roofs in reducing carbon dioxide emissions. Additionally, the green roof incurs a minimal financial burden, constituting only 0.51% of the overall project cost.