The ‘cradle to grave’ life cycle assessment was not only conducted for Isonat, the leading hemp fibre insulation, but also Thermafleece.  The materials studied are comparable in many environmental impact categories to materials given an A rating in the BRE Green Guide to Specification.

The study confirms that natural fibre insulation reduces global warming potential by locking up atmospheric CO2 in the fibre and binder materials and storing it during the life of the product. Following disposal by landfill or composting, only a partial release of the CO2 locked up would be expected.

UK manufacturing could play a further role in improving the environmental impact of natural fibre insulation. Scaling up production would halve the energy required for plant fibre production and manufacturing the insulation in the UK would reduce the environmental impacts from transportation.

Further ways forward are proposed for optimising the environmental profile for natural fibre insulation, which would form logical next steps for this emerging industry.

Dr John Williams, NNFCC’s Technology Transfer Manager for Renewable Building Materials comments “The producers are already working on process improvements, and the findings of this study support ongoing work to increase production efficiencies and costs. Additional product developments and retailer acceptance will improve the market share of natural fibre insulation in the UK. It’s good news that this goes hand in hand with environmental benefits”.

The NNFCC and Defra study is entitled ‘Life Cycle Assessments of Natural Fibre Insulation Materials (NNFCC Project 07-007; Imperial College). To download a copy of the report, Click here. The LCA followed the principles of the ISO 14040 series of international standards for life cycle assessment.