Life cycle carbon assessment of decarbonising UK’s hard-to-treat homes: A comparative study of conventional retrofit vs EnerPHit, heat pump first vs fabric first and ecological vs petrochemical retrofit approaches

How far can low emission retrofit of terraced housing in Northern Ireland go?

“…With further consideration of the design of the retrofit and further reflection on material choices, Net Zero emissions may be achievable for this house. The substitution of materials with natural, or lower carbon, alternatives may be one way of reducing embodied emissions further, with the benefits of such approaches highlighted by Mohammadpourkarbasi et al (2023). Furthermore, with double glazing already installed is there a benefit in replacing these windows with new triple-glazed units or are operational savings undone by the embodied carbon costs?…”

“…Whilst (Satola et al 2022) argue for the integration of a whole-lifecycle approach to emissions, for both new build and retrofit, this is currently not always the case. Various studies have examined the operational and embodied emissions associated with retrofit as well as the impact retrofit depth can have on emissions (Famuyibo et al 2013, Colli et al 2018, Vavanou et al 2022, Mohammadpourkarbasi et al 2023, Shibata et al 2023, but the lifecycle stages considered vary. Fewer studies have used EN 15978:2011 as the methodological approach for the LCA and fewer still consider all lifecycle modules within this standard.…”

“…Regardless of the differences in reporting the various LCA modules the studies highlighted in table 2 some of these also explore the impact retrofit depth can have on lifecycle emissions. The impact of retrofit depth is illustrated in the studies by Vavanou et al (2022) and Mohammadpourkarbasi et al (2023) where progressively deeper retrofit scenarios reduce lifecycle emissions. It is also apparent, in both of these studies, that increasing retrofit depth shifts the emissions balance from operational emissions towards embodied factors, although operational emissions often remain the largest single source of GHG emissions.…”