BIG Energy Upgrade Environmental burden of insulation materials for whole building performance evaluation.
This report assesses the whole life performance of external wall insulation systems which have been installed to improve the thermal performance of the building fabric of hard to treat homes. Work conducted includes the calculation of the environmental impacts of insulation, estimation of payback periods and discussion of later life cycle stages.
The environmental impact of phenolic foam insulation boards, expanded polystyrene and rockwool boards are quantified and compared. Expanded polystyrene has the lowest environmental impact in the majority of the sixteen categories considered. A wider comparison of embodied carbon also including woodfibre board and PIR boards found woodfibre board to have the lowest embodied carbon by a significant margin – due to carbon sequestration within the wood. The end of life stage was highlighted as an area requiring further work by the industry to ensure that the render and adhesive layers can be separated from the insulation boards once the systems are dismantled so that the insulation can be recycled rather than sent to landfill or incinerated.
Briefing sheets (included as appendices) highlight key information about retrofitting British Iron and Steel Federation (BISF) and Wimpey No Fines homes. Two briefing sheets summarise information on phenolic foam boards and expanded polystyrene boards. A full report on robustness testing can also be found in the appendices.