News
Let it Breathe: Energy Efficiency Meets Historic Buildings
13 November 2025
Get to know your building before your start tinkering with it.
Jemima Webb Heritage Advisor London
Energy efficiency is now front and centreto historic building conservation, as councils across the country revise their local plans to align with Climate Emergency declarations and the Government’s 2050 Net Zero agenda.
That's a tall order when you're dealing with buildings that were here long before insulation boards, cavity walls, or double glazing were even a thought. But while they might not boast the EPC ratings of new build. Traditional buildings were designed with their own clever kind of sustainability – one that often outlasts modern materials.
Unlike many newer homes, traditional buildings manage moisture, air and heat in a completely different, and often more resilient way. The natural materials in traditional construction absorb and store moisture and heat, releasing it later. These traditional buildings "breathe", quite literally. This means you need to have a sensitive whole house approach before simply applying modern energy efficiency solutions. If you don't let these buildings breathe as they were designed to, you risk doing harm not just to the fabric of the building, but also to the comfort and health of those living inside it.
Historic England has recently published revised two guidance notes on energy efficiency and historic buildings:
- Understanding the Environmental Performance of Historic Buildings for Conservation
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Adapting Historic Buildings for Energy and Carbon Efficiency
Here's a quick round up.
The first advice note provides guidance on assessing the environmental performance of historic buildings. This includes additional information on the building environmental performance assessment (BEPA).
The three factors which affect the performance of a historic building are:
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Building Fabric: the building's construction, materials and condition;
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People: those using the building and how they are managing their uses; and
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Services: the equipment added to improve building usability, such as lighting, heating, cooling and mechanical ventilation.
The key takeaway? Carry out a BEPA. This process help you understand how the building worked originally, how its performance has changed over time, and what can be done to improve it without compromising its heritage or creating new environmental risks.
In short: get to know your building before you start tinkering with it.
Thie second advice note provides clarity on the recent updates to the Building Regulations Approved Documents for Part L, which aims to balance energy efficiency goals with the unique character of the historic buildings.
Existing buildings will need to comply with this when installing or improving thermal elements or replacing building services, constructing extensions/conservatories/porches, or critically when undertaking a change of use.
As with other energy efficiency improvements, these works could cause technical conflicts with the existing construction and the new ‘improvements’, such as increased moisture accumulation, rot or decay, as well as unacceptable damage to the historic significance of the building.
It is important to note that listed buildings, buildings in conservation areas and scheduled monuments do not need to comply fully with the energy efficiency requirements, where to do so would unacceptably alter the dwelling’s/building’s character or appearance (Section 0.8 of Volume 1 and Section 0.12 of the Approved Document L).
Our historic buildings have stood the test of time precisely because they were designed to adapt – to their environment, to the seasons, to us. The challenge is now to help them continue doing that, without smothering what makes them special in the first place. After all, the best way to keep these buildings sustainable is to let them breathe.
If you would like any advice about sensitive retrofit, Heritage Potential would be happy to help – please get in touch!
