Retrofitting to decarbonise housing

Retrofitting to decarbonise housing

By Samuel Houlberg, Policy Fellowships Coordinator, CSaP

The need to redevelop the UK’s housing stock is one of the most pressing challenges facing the nation today. Housing accounts for 16% of the UK’s total carbon emissions, making it the second highest sector overall, after surface transport.

A panel at CSaP’s 2024 Annual Conference tackled the problem head on. Chaired by Becci Taylor (Director of ARUP), the panel included Dr Ronita Bardhan (Department of Architecture, University of Cambridge) and Dr Shaun Fitzgerald (Director of the Centre for Climate Repair). They presented their analyses of how the UK can best retrofit old housing for decarbonisation, and argued for the need to take a systemic approach that responds to the range of difficulties and opportunities that will arise.

Data and modelling

Dr Bardhan began by highlighting the need for a comprehensive understanding of the data in order to most effectively plan for retrofitting. Her work utilises multimodal data sets to not only demonstrate the energy implications of retrofitting housing, but also to enable a holistic perspective that incorporates social repercussions and various forms of depravation. This information helps identify new priorities. For example, combined data will make it possible to recognise regional microclimates that require a different emphasis on summer cooling rather than on winter insulation. However, Dr Bardhan’s work presents a challenge moving forward: current models of consumption and potential savings are based on historical trends which may be invalidated by accelerating climate change.

Engineering Needs

Dr Fitzgerald then offered insights from his engineering perspective. He emphasised that the real aim of decarbonising existing homes should be to stop burning fossil fuels and to reduce energy consumption. This transition requires moving to renewably-sourced energy and adopting technologies like heat pumps. Heat pumps could eliminate reliance on fossil fuels to heat the home but they also present new engineering challenges, needing the greater surface area provided by larger radiators or under floor heating in order to be efficient. Larger gains may be achieved by reducing energy consumption in the first place. While effective insulation and air tightness will be essential, for example, currently houses are designed to be leaky for health reasons, preventing the build-up of black mould. A number of obstacles therefore lie in the way of decisive retrofitting.

The implications of retrofitting

As the panel moved onto the question and answer section, the broader social implications of retrofitting in housing were raised. Dr Bardhan firmly agreed, stressing the health benefits associated with improved housing stock. For her, this reinforces the value of multimodal data sets which can provide a holistic understanding of a variety of consequences from redeveloping housing. In Scotland, for example, policymakers include housing as a central component of public health. For Becci Taylor, then, this demonstrates the need for a systems approach when considering retrofitting old housing that targets investment for maximal benefits.

However, several members of the audience argued that they needed greater clarity about how the decarbonised housing can best be achieved—the current incentives system is complex and opaque. Furthermore, the rental market limits comprehensive retrofitting campaigns since landlords lack incentives to make the necessary changes. Dr Bardhan again emphasised the importance of accessible data, to enable multifaceted decision making, better engagement between academics and policymakers, and to put pressure on policymakers. Dr Fitzgerald proposed some simple fixes that might improve the issue such as publicising information about the value of retrofitting and requiring landlords to carry out retrofitting of their properties between tenancies. Renters would thus see improved housing conditions without the disruption of building work while in situ.

Making the case for retrofitting housing to policymakers

The discussion moved on to community responses to the need to retrofit housing. Significant regional disparities exist in access to support for retrofitting. What role can communities or even individual streets therefore play in bringing together demands for retrofitting? Becci Taylor described place-based transition as the ‘holy grail’ for retrofitting policymakers, reducing costs and introducing new economic models that benefit the whole community. Dr Fitzgerald highlighted the need to build trust in a high standard of work delivery, and Dr Bardhan mentioned mis- and dis-information as threats to cohesive community responses. Both agreed on the need for community engagement to achieve net zero goals.

In a final question, the panel discussed how different levels of government can collaborate in order to bring about the needed retrofitting reforms. Dr Bardhan, advocated for building a large data set to inform local government about the varied benefits that can accrue from retrofitting old housing. This would help to build multi-level accountability that responds to several targets alongside net zero. Becci Taylor suggested that greater devolution would afford local government the flexibility and adaptability to develop retrofitting programmes that most effectively respond to local conditions and needs. And Dr Fitzgerald agreed, underlining the need for investment in local government to develop the capacity in local authorities to produce significant changes.

Becci Taylor concluded the panel by asking each member for one change they would make to enable the retrofitting of old housing today. Dr Bardhan reiterated the need for better data systems that demonstrate the co-benefits of retrofitting and reflects future realities. Dr Fitzgerald, meanwhile, emphasised that financial incentives are necessary but not sufficient to facilitate the decarbonisation of old housing. By learning about when people are most prepared to make changes, we can provide them with the right information, at the right time, with the right incentives.

The need to decarbonise old housing stock is an essential issue. If done correctly, it could significantly contribute to net zero targets. The panel showcased practical approaches to retrofitting and highlighted the substantial benefits and challenges involved, underscoring the importance of systemic, well-informed and community-engaged policies. However, they also demonstrated the significant obstacles, both practical and political, that will have to be overcome in order to make meaningful headway in the campaign to renew the housing stock for the twenty-first century.

Image by Su Ford, CSaP Centre Coordinator