Temporal myopia in building Life Cycle Assessment? Granular versus coarse dynamics in climate change and grid decarbonisation

Source abstract

Purpose Buildings exert significant biophysical pressures through environmental impacts. Whilst Life Cycle Assessment (LCA) is widely applied, static and global warming potential-focused approaches overlook dynamic factors such as climate change, electricity grid decarbonisation and impacts beyond carbon. This study applies higher temporal resolution to capture interactions between buildings, evolving climate and electricity systems. Methods A dynamic LCA framework was applied to three London buildings, two residential and one office, following EN ISO 15978:2011+A2:2019 and UK guidance. Fifteen scenarios combined two climate trajectories, RCP 4.5 and RCP 8.5, with multiple grid decarbonisation pathways for the UK, EU and several other countries and regions. Future hourly UK electricity mixes to 2050 were modelled using PyPSA-GB and validated against historical data. Embodied impacts were modelled dynamically using future country or region-specific electricity mixes via a Python-based tool. Operational energy demand was simulated using dynamic thermal modelling and linked to evolving grid mixes. All EN ISO 15804:2012+A2:2019 impact categories were assessed using static, annual and hourly resolutions. Results Climate change and grid decarbonisation jointly reshape lifecycle impacts. Warming climates reduce heating and hot water demand whilst increasing cooling, particularly under RCP 8.5. Annual and hourly approaches agree for residential buildings under grid decarbonisation alone. When climate change is included, high temporal resolution becomes critical for UK offices, revealing increases in human toxicity and land use due to daytime biomass and photovoltaic generation. Hourly assessment also shows greater land use benefits from on-site photovoltaics. Conclusions Temporal granularity strongly influences building environmental performance, especially in UK offices