Why historic homes need a gentler approach to heat

Period properties are not like modern houses. They were built with solid walls, timber frames and breathable materials that allow moisture to move through the fabric. When we try to heat them like a new-build — sealing every gap and wrapping them in impermeable insulation — we can trap damp inside walls and floors. That leads to rot, mould and a building that feels colder, not warmer. The goal is to keep a historic property warm and efficient without suffocating it. That means working with breathability, controlling draughts rather than eliminating all air movement, and adding insulation that lets walls breathe.

Understanding breathability in solid-walled buildings

Traditional buildings rely on lime mortar, lime plaster and breathable paints to manage moisture. These materials absorb water vapour when the air is humid and release it when conditions dry out. If you replace them with cement render, gypsum plaster or plastic-based paints, you block that process. Moisture then gets trapped, often leading to crumbling masonry, damp patches and decayed timbers. Any insulation or repair you choose should be vapour-permeable. Natural materials such as sheep's wool, wood fibre, hemp and cork are excellent choices. They also tend to be better for the building's long-term health.

• Use lime-based renders, plasters and breathable paints.
• Choose natural insulation: sheep's wool, wood fibre, hemp or cork.
• Avoid cement, gypsum and impermeable sealants on solid walls.

Draught control without sealing the building

Draughts are uncomfortable, but some air movement is essential in an old house. The trick is to stop cold air blowing across you while keeping enough ventilation to prevent condensation. Start with the obvious culprits: windows, doors, chimneys and floorboards. Heavy curtains with thermal linings make a huge difference, especially in country houses with large sash windows. Draught excluders on doors and letterboxes are cheap and effective. For windows, secondary glazing is usually the best option in a listed building — it reduces draughts and noise without sealing the original frame. Chimney balloons or draught excluders stop cold air pouring down when the fire is not in use.

• Hang heavy, lined curtains and close them at dusk.
• Fit draught excluders to doors, letterboxes and keyholes.
• Install secondary glazing rather than replacing historic windows.
• Block unused chimneys, but remove the blocker before lighting a fire.

Never block air bricks, sub-floor vents or trickle vents. They protect timbers from rot and keep the building healthy.

Insulating sensitively: where to add and where to avoid

Loft insulation is usually the easiest and most cost-effective improvement. Use a breathable material and keep eaves ventilation clear so air can circulate through the roof space. Avoid insulating directly between rafters unless you use a breathable system designed for historic roofs. For walls, internal insulation can work if it is breathable and installed with a vapour-open build-up. Wood fibre boards with lime plaster are a good option. External insulation is rarely appropriate for period properties, as it changes the appearance and can trap moisture. Floors need care: do not seal suspended timber floors with concrete or impermeable membranes. Instead, use breathable rugs, carpets and underlays, and leave underfloor vents clear. If your property is listed, check whether consent is needed before making changes.

• Loft: use natural insulation and keep eaves vents clear.
• Walls: choose breathable internal systems such as wood fibre and lime.
• Floors: avoid sealing; use breathable coverings and keep vents open.

Heating a period home efficiently

Historic houses often have many rooms and high ceilings, so heating every space to the same temperature wastes energy. Zone your heating and use thermostatic radiator valves to keep unused rooms cooler. A modern condensing boiler is fine, but make sure it is correctly sized — oversized boilers cycle on and off and waste fuel. Smart controls help you heat only when needed. If you have open fires or wood burners, burn dry, seasoned wood and have the flue swept regularly. Heat pumps can work in older homes, but they need careful design and a well-insulated, draught-proofed building. Underfloor heating is usually unsuitable for solid floors because it can drive moisture into the walls. Radiators, run at a steady lower temperature, are often kinder to historic fabric.

• Zone heating and fit thermostatic radiator valves.
• Service the boiler annually and bleed radiators.
• Burn dry, seasoned wood in stoves and open fires.
• Seek expert advice before installing a heat pump or underfloor heating.

Seasonal checks and daily habits

Keeping a historic property warm is as much about maintenance as technology. Clear gutters and drains before winter, check roof tiles and flashings, and make sure rainwater goods are not leaking into walls. Inside, open windows briefly each day to purge moist air, and use extractor fans in kitchens and bathrooms. Wipe condensation from windows before it runs down and damages frames. In a country house, close doors to unused rooms and use curtains and shutters at night. Keep a simple log of damp patches, draughts and heating performance so you can spot changes early. With a breathable, balanced approach, you can keep a period property comfortable and efficient without harming the fabric that makes it special.