Around 20% of UK carbon emissions come from housing, and 80% of homes that will still be standing in 2050 are already built. Retrofitting these existing homes for energy efficiency is therefore critical to meeting net-zero targets, but current approaches often rely on synthetic materials like plastic foam insulation, which carry their own environmental costs—sometimes cancelling out the carbon savings from reduced energy use. Bio-based materials such as timber, cork, mycelium, and crop fibres could store carbon and improve indoor air quality, yet they remain underused in the UK compared to other European countries. This project will co-design, test, and monitor prototype retrofitting solutions using bio-based and non-extractive materials, working directly with two communities in Bristol and Swansea. The team will focus on low-rise council-built homes from the 1920s–1940s, of which roughly 1.1 million are still occupied. If successful, the research could shift how the UK approaches housing retrofit—replacing carbon-intensive materials with renewable alternatives, reducing damp and mould problems, and supporting local supply chains and green jobs. It also aims to change householder attitudes toward natural materials and sustainable living, creating a lasting legacy of behaviour change and design skills.
View original technical description
The housing sector is responsible for around 20% of the country's total carbon emissions and with 80% of the homes that will be occupied in 2050 already built, retrofitting the country's existing housing stock to improve energy efficiency, and reduce carbon emissions, is critical to achieving the UK's net-zero targets. Retrofitting existing houses is an infrastructure priority for the UK Government; it is also a significant design challenge. Changes in housing fabric are essential to ensure that new low carbon heating and cooling solutions work effectively. Poorly executed retrofit measures can lead to unintended negative consequences, including increased problems with damp and mould, and reduced indoor air quality (affecting human health). Poor design can also cause damage to building fabric and cultural heritage. Current retrofitting approaches also rely heavily on synthetic and non-renewable materials, such as plastics and foam insulation, which can have negative environmental impacts. In some cases, the embodied carbon emissions of retrofitting measures can even exceed the carbon savings from reduced energy use. Using bio-based and non-extractive materials in retrofitting offer promising alternatives, but currently occupy a small market share. Bio-based materials are derived from renewable resources, such as crops, mycelium, cork and wood, and have the potential to significantly reduce carbon emissions and environmental impact. Non-extractive materials are derived from a supply chain based on circular reuse and recycling of waste. Plant based materials, including timber, absorb atmospheric CO2 through photosynthesis, forming a 'biogenic carbon store'. As well as environmental benefits, bio-based products and systems offer energy efficient, healthy, and sustainable improvements to existing homes. However, despite their comparatively lower embodied carbon, the use of bio-based materials, compared to a number of other European countries, remains under-utilised in the UK. Our project, the Transforming Housing and Homes for Future Generations Green Transition Ecosystem (GTE), will lead innovation through co-design, in a regional partnership between the GW4 universities (Bath, Cardiff, Bristol, and Exeter) and businesses, local authorities, and council-built estates and community groups. We will work with householders, community groups, local authorities, social landlords, the construction industry, and other key stakeholders, to co-create a green transformation. Centred on a process of design research, through transdisciplinary working, cross-sectoral and community participation, we will design, test, implement and monitor innovative prototype solutions to improve the quality of energy inefficient low-rise council-built housing. We will also seek to create a legacy of positive behaviour change, supporting job creation, local and regional supply chains, and strengthen local delivery capacities. We will create design proposals for Beyond Net Zero liveable homes through remodelling housing built by councils between 1920-1940, which account for approximately 1.1 million of the homes still in use in the UK today. We will work with two communities in Bristol and Swansea to develop and demonstrate possible solutions. Our design led process will include co-design, digital modelling, prototyping, and testing of alternative options. Our solutions will create delight through improving spatial quality, well-being, affordability and ease of construction. Our design research will also promote the transition to living well through co-design methodologies enabling positive behaviour change including attitudes towards natural materials and sustainable living, fostering diversity, and supporting green transition goals. Through educational and wider community engagement, in partnership with our communities and the Future Observatory, we will also further retrofitting design skills.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know