Heritage and listed buildings

Improving the energy efficiency of a heritage home (such as a listed building or a property in a conservation area) requires a delicate balance between modern comfort and preserving historical character.

In the UK, traditional buildings (typically those built before 1919) work differently than modern ones—they are designed to be “breathable,” allowing moisture to move through the fabric of the building.

The importance of “Breathability”

Traditional solid-wall buildings use porous materials like lime mortar, timber, and brick. These materials absorb moisture and then release it (evaporate it) naturally.

If you use modern, non-breathable materials (like cement render or plastic-based foam insulation) on an old building, you can trap moisture inside the walls, leading to damp, rot, and structural damage.

Energy upgrades in heritage homes

1. Draught-proofing

Often the most effective and least invasive upgrade. Use specialist brushes and strips that are sympathetic to the original joinery. For original sash windows, professional draught-proofing can reduce heat loss by over 80% without changing the look of the window.

2. Secondary glazing

If you aren’t allowed to install double glazing, secondary glazing is a highly effective alternative. A second, discrete pane of glass is fitted on the inside of the existing window. It improves thermal performance and acoustics while being entirely reversible.

3. Breathable insulation

If you are insulating solid walls, use natural, “vapor-open” materials such as wood fibre boards, hemp, or sheep’s wool. These allow moisture to continue moving through the walls.

4. Attic and floor insulation

Insulating a loft in an old building is usually straightforward, but you must maintain excellent ventilation in the roof space to protect the original timbers.

Planning and permissions

Listed buildings

You will almost always need Listed Building Consent for any work that affects the character or appearance of the building. This includes internal changes like wall insulation or replacing floorboards.

Conservation areas

Rules are slightly more relaxed than for listed buildings, but you may still face restrictions on external wall insulation, solar panels, or window replacements if they face a public highway.

The “Pre-application” Step: We strongly recommend contacting your local council’s conservation officer before starting any energy efficiency project. They can provide invaluable advice on what is likely to be permitted for your specific property.

Low-carbon heating (Heat pumps)

Heat pumps can work very well in old buildings, but only if the heat loss has been addressed first through draught-proofing and insulation. Because old radiators are often larger than modern ones, they sometimes work surprisingly well with the lower temperatures of a heat pump.

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