Retrofitting of energy efficiency measure in historic homes

The UK Government’s recent review explores the complexities surrounding the retrofitting of energy efficiency measures in historic homes, balancing the preservation of cultural assets with the imperative to achieve Net Zero targets. With buildings contributing to 17% of the UK’s carbon emissions and a substantial portion of the building stock predating 1944, including listed dwellings and homes in conservation areas, the need for aligned energy efficiency improvements becomes evident.

In this blog BWF Technical Director, Kevin Underwood discusses the significance of retrofitting over new construction, emphasising the environmental benefits and tackling the barriers identified in the government’s review.

The Government recently published its review of the perceived barriers to retrofitting energy efficiency measures into historic homes in England. Historic homes are cultural assets that need to be protected, conserved and adapted for the benefit of future generations. Ensuring they can be adapted to accommodate energy efficiency measures is key to ensuring their long-term survival.  The Government believes that improving their energy efficiency and protecting their historic and architectural interest are compatible and complementary goals and sees the appropriate retrofit of historic homes as part of the solution to achieving Net Zero.

The Climate Change Committee’s 2023 Progress Report to Parliament stated that buildings remain the UK’s second highest-emitting sector, accounting for 17% of total carbon emissions. The Valuation Office Agency’s 2022 Council Tax: stock of properties report showed that UK has the oldest building stock in Europe, with 5.9 million buildings (21%) built before 1919 and a further 4.3 million (15%) before 1944. Historic England’s 2022 data published in the Designated Assets, Protected Areas and the Built Environment report showed there are approximately 350,000 listed dwellings in England, and an estimated 2.8 million homes in conservation areas.

The most sustainable building is often one that already exists. Successful retrofit leads to the continued use and care of buildings to prevent waste, and it avoids the increase in carbon emissions from new builds.

Embodied carbon accounts for the carbon emitted over the whole lifecycle of a building, including during construction, use and demolition. Evidence presented in Historic England’s 2020 Understanding Carbon in the Historic Environment: Scoping Study demonstrated that if embodied carbon emissions are excluded, the carbon emissions of a new building can be underestimated by up to 31% over 60 years. Research presented in the report, Embodied Carbon: Three reasons we should care, available from the Open University website, showed that making energy efficiency improvements to existing buildings is at least 4% more beneficial, in lifecycle carbon terms, than to demolish and replace. In some cases, this benefit can increase to nearly 60%. Maintenance, periodic renewal, and conservation-focused refurbishment have the potential to save between 30% and 50% of carbon emissions and, additionally, to save up to 40% in energy consumption.

The Government’s review focussed on the barriers to the installation of energy efficiency measures which reduce energy demand, e.g. double glazing and insulation, and the installation of low carbon heating measures, e.g. heat pumps, both of which are essential factors in achieving Net Zero targets.

There were five key areas identified as affecting work on historic homes, these were,

• The planning system

Where planning permission is required, the local planning authority is subject to special heritage legal duties which require them to consider the desirability of preserving the listed building or conservation area when determining the application. These legal duties underpin the heritage planning policies in the National Planning Policy Framework, which emphasise the importance of identifying the heritage impacts, and set out the tests to be applied by local planning authorities in determining applications with impacts on heritage assets.

Separate to planning permission, works to listed buildings which would affect their special architectural or historic interest also require listed building consent from the local planning authority. Unlike planning permission, these works could include internal alterations and so could extend to a wider range of energy efficiency improvements where those works impact on the special interest of the building.

• Local authority skills, training, and capacity

Many local planning authorities have no conservation officer and either share a post with neighbouring councils or buy-in heritage advice from consultants. In addition, the high turnover of staff in planning departments is exacerbated by the underlying problem of under-resourcing and lack of training. The government recognises that local authorities, as well as the wider planning sector, face serious capacity and capability challenges which have resulted in delays, including in the processing of planning applications, impacting on homeowners and developers alike.

• Guidance and information

Historic England’s 2022 Survey of Listed Building Owners and Occupiers found that over half (54%) of owners and occupiers think it is difficult to find reliable guidance about how to retrofit listed homes. The range of information sources on retrofitting which owners turn to is broad, varied, and includes information from local councils (16%), architects (14%), builders (13%), professional organisations (9%), Historic England (8%), UK Government sources (7%), and local heritage organisations (4%).

• Construction industry skills, training, and capacity

The loss of skills in the heritage construction industry is a key barrier to adapting historic homes. This view is supported by the Construction Industry Training Board (CITB) in England, Scotland and Wales Construction Skills Network Industry Outlook 2023-27, published January 2023, which suggests that the heritage sector is facing an unprecedented skills crisis in two ways: the skills gap and workforce shortages. There is also a need to upskill mainstream construction workers to ensure the industry understands appropriate methods to adapt historic buildings.

• Affordability and financial incentives

Historic England’s 2022 survey of owners and occupiers of listed buildings found that cost was a common barrier to retrofitting, more so than lack of knowledge, difficulty finding a contractor, the disruption of works, or concerns around damaging the character of the home. Stakeholder feedback on affordability and cost also referenced the VAT treatment of repair and maintenance services (subject to 20% VAT) and compared this to the zero-rate applied to new builds, which was introduced to increase housing supply.

The BWF is encouraged by this new guidance from the Government and hopes that activities coming from this initiative will ease concerns associated with retrofitting energy efficiency measures in historic homes. The BWF will continue to work with its members to develop guidance in this area through its recently formed heritage and conservation focus group, and the BWF’s Woodworking Industry Training Forum (WITForum), which was established to tackle the skills and training shortages facing the woodworking and joinery manufacturing sector, will be looking into the issues raised.