Why older British homes need a different approach

If you live in a Victorian terrace, a 1930s semi or a stone cottage, the usual advice about cavity wall insulation and airtight modern builds does not quite fit. Many older homes have solid brick or stone walls, no cavity to fill, timber windows and suspended floors. They were designed to breathe, with air moving through chimneys, floorboards and lime mortar.

That matters because the wrong improvements can trap moisture, leading to damp patches, mould and rotting timbers. The sensible strategy is to cut draughts and heat loss step by step, starting with the cheapest and least invasive measures, and to use materials that let the building manage moisture the way it always has. Here is how to make a period property warmer without undoing what makes it special.

Draught-proofing: the cheapest wins come first

Before spending thousands on insulation, spend a weekend on draughts. A leaky home can lose a surprising amount of heat through gaps you barely notice, and the fixes are inexpensive and reversible.

• Chimneys — an open flue is an express route for warm air. A chimney balloon or a sheep's wool draught excluder makes a real difference in unused fireplaces. Remove it if you light a fire, and never block a flue serving a working boiler or stove.
• Sash windows — brush or sprung seals fitted into the staff beads stop rattles and draughts while keeping the sashes sliding. Avoid sealant that glues the window shut; older timber needs to move.
• Doors — a letterbox flap with a brush, a keyhole cover, and a brush or wiper seal around the frame. A well-fitted door curtain also helps.
• Floorboards and skirting — gaps between boards and along the skirting can be sealed with flexible mastic or paper-backed fibre strips. Leave a little movement in historic boards.

Do not seal everything. Kitchens and bathrooms need extract ventilation, and trickle vents on windows should stay open. Balance is what keeps a house dry.

Loft insulation done properly

If you have a cold, accessible loft, this is usually the best value improvement available. The recommended depth for mineral wool is around 270mm, but the detail matters more than the number. If your joists are shallow, lay insulation between them and then cross-lay a second layer at right angles to cover the timber and avoid cold bridging.

Keep the eaves clear. Pushing insulation into the ventilation gap at the roof edge traps damp air and can rot the roof timbers. Insulate and draught-proof the loft hatch, and lag any pipes and cold water tanks up there so they do not freeze. If you use the loft for storage, raise the floor on battens rather than squashing the insulation flat. Room-in-roof and flat roof spaces are a bigger job and worth professional advice.

Modern controls for an older heating system

Many period homes still run on a simple timer and one thermostat in the hall. Adding control is often more effective than replacing the boiler.

• Fit thermostatic radiator valves on every radiator except the one in the room with the main thermostat, so unused bedrooms stay cooler.
• Lower the boiler flow temperature to around 55–60°C if you have a condensing boiler. It takes longer to warm up but condenses more efficiently, cutting gas use.
• Consider weather compensation or a smart thermostat with proper schedules, rather than heating an empty house all day.
• Have the system flushed and a magnetic filter fitted, so sludge does not clog radiators and reduce their output.

Windows, walls and the bigger decisions

Original sash windows are rarely as bad as their reputation. Repairing, re-puttying and draught-proofing them, then adding slim secondary glazing, usually costs less than replacement and keeps the character — and the look — of the street. Thermal curtains on a proper track, with a pelmet, work well too.

Solid wall insulation is the expensive end of the scale. Internal insulation loses floor space and creates cold bridges at joists; external insulation changes the appearance and may need planning consent. If you go ahead, choose breathable materials such as wood fibre or cork with lime finishes, and avoid cement render and impermeable boards that trap moisture in the wall.

Costs, consent and a sensible order of work

Check your Energy Performance Certificate for a rough idea of where the biggest losses are, and ask your local council about grant schemes for insulation and heating — eligibility changes, but support does exist. VAT relief applies to many energy-saving materials, so ask installers to itemise.

Work in this order: draught-proofing, loft insulation, heating controls, then windows and walls. If your home is listed or in a conservation area, get consent before changing windows, doors or external finishes. Use accredited installers, keep guarantees, and take photographs before you start. Do it gradually and your period home will be noticeably warmer, cheaper to run and still recognisably itself.