Home insulation being applied to a door

Insulation is key to a warm and toasty home. In a poorly insulated house, up to a third of your heat can escape. But don’t despair! Your home can be insulated, and you can lower your heating bills too. Keep reading to find out how…

Are your walls letting heat escape?

Cavity walls

If your home was built after 1920, it’s likely that your external walls are made of two layers with a gap in between — these are called cavity walls. This gap lets heat escape, and can often be filled by a professional in a couple of hours.

Solid walls

If your home was built before 1920, chances are you have solid walls. Unfortunately, solid walls have no ‘gap’ and let through twice as much heat as cavity walls. The good news? By insulating your walls, either from the inside or the outside, you can cut heating costs considerably.

Most modern homes, built after 1990, have wall insulation to keep the heat in.

Is it worth it?

By insulating your walls you can create an even temperature in your home, prevent condensation on the walls and ceilings, and reduce the amount of heat that builds up inside your home during hot weather. Plus, according to the Energy Saving Trust, the average semi-detached house can save £160 per year by insulating cavity walls, and £260 per year by insulating solid walls.

You can use the Energy Saving Trust’s Home Energy Check tool to see what kind of walls you have and the next steps if you decide to insulate.

Laying insulation in the loft with protective mask on

Laying insulation in the loft with protective mask on

How else might heat be escaping?

The proof’s in the roof

Heat rises, and in an uninsulated home a quarter of the heat is lost through the roof. Insulate your loft, attic or flat roof to a recommended depth of 270mm to save energy and money.

Don’t be daft — block the draught

Did you know 20% of all heat is lost through ventilation and draughts? To test your home, hold the palm of your hand up against all the windows, doors and loft hatches. If you feel cold air coming through, that means warm air is escaping.

Tank you very much

Insulating hot water tanks can cut heat loss by more than 75%, and keep your water hot for that much-needed bath after a long day at work. British Standard ‘jackets’ for your water cylinder can be found in all good DIY stores and are cheap and easy to fit.

If you already have one fitted around your cylinder, make sure it’s at least 75mm thick.

Double up

By trapping air between two panes of glass, double-glazing creates an insulating barrier that reduces heat loss, noise and condensation. If you can’t afford to replace all windows, choose the rooms in your house that you spend the most time in, and that are the most expensive to heat.


If you’d like any more advice on insulation, tools and tradesmen, contact the Energy Saving Trust.