Challenge outline: Low-carbon building materials with a focus on suitability for retrofits, in particular, insulation materials. The building industry is a carbon intensive sector and a large contributor of greenhouse gas emissions. With Britain’s building stock ageing, there is a need to improve the energy efficiency of existing buildings. We need to make the use of low-impact, low-carbon materials as standard in the energy efficiency retrofits of these buildings and must scrutinise products for their carbon footprint. Key aims/objectives: Using the list supplied, prepare a report detailing which are the most environmentally sound, energy efficient and cost-effective building insulation materials to use: • cork • hemp • wood fibre • sheep’s wool • expanded rubber • reeds • straw • cellulose • flex • coconut fibre Suggested areas of focus to aid research: 1. Details about the material (in order of importance: material source, production cost, expected lifetime, its insulation properties, energy intensity of production process, form of disposal, availability etc) 2. Has it been approved as a building material by regulating bodies (e.g. BBA approval) and does it comply with building regulations? 3. Does it perform best in combination with other materials, is so which, or in isolation? 4. Pros & Cons of the materials, e.g. material strength, waterproof, fire retardant etc 5. Investigate existing low-carbon alternatives for the current market-leading insulation products, e.g. to replace Celotex insulation board etc. Stretch Questions: 1. Analysis of new materials that look promising, e.g. mycelium bricks 2. Finding suppliers of these materials (ideally UK-based but can extend to international level)