Is your home well insulated?

Temperature wise, winter 2020/21 has on the whole been fairly mild - but next year's might see us plunged into a polar vortex. So if you've not checked up on how your building is insulated, now's a good time to do so

Houses need to be well insulated

If your house was built after 1920, chances are the external walls have two layers, with a gap or cavity between them. You can find out if that's been filled with insulating material, and if not, get it done because more than 30 per cent of heat is lost through walls. 

Do you despair of your rising energy bills? And do you wonder why you have the heating turned on for what feels like an eternity, yet your house or flat doesn't say warm for long?  

If so, then it's more than likely your home is poorly insulated - a problem with properties built before then 1990s and a real problem if you live in Victorian housing stock.

However, there are ways you can make your property more airtight via various forms of home insulation. This means you'll keep more of that expensive heat inside rather than it flowing out through your walls and windows.

Cavity wall insulation could save your hundreds of pounds a year on fuel bills.
If you have a loft extension ensure that floor and roof and eaves are insulated

Data suggests that an un-insulated home could be costing you an extra £500 a year on your energy bills. And in case you assume that the house you move into will have at least have had the loft insulated, well don't make assumptions.

Photographer Mike Gideon bought a house in east London, built in the 1930s and occupied most recently by a builder...yes, a builder...But when he and wife Anna looked into the loft 'which is a very large space', they were horrified to see it was completely uninsulated. 'I literally could not believe it!,' says Gideon.

There are many types of insulation that can help you save money and energy. Obviously the age of your property will determine what to do in terms of insulating the walls, and for more detailed information contact The Energy Saving Trust or a reputable insulation company.

Solid wall insulation

In older properties without cavity walls, solid wall insulation is the best option and while costs may be in the thousands rather than hundreds of pounds, you will  in the long run you'll save a lot on energy bills.

Derbyshire insulation company Westville Group explains that to insulate a solid wall from the outside, a layer of insulation material (such as Permarock boards) is fixed to the walls with mechanical fixings and adhesive, then covered with protective layers of render or cladding. Since the Grenfell Tower fire in 2017 there is much greater awareness of the need to use fire retardant materials, not polystyrene blocks. 

The finish can be smooth, textured or painted, tiled, panelled or finished with brick slips to provide a real masonry brick finish. The finish will cover the whole of the outside of your property, including existing brickwork, and may change its appearance. This does mean you'll need to check with your local authority as to whether you'll need planning permission.

Cavity Wall Insulation

Houses built with two layers of wall should have the cavity between them filled with a mineral wool insulating material to minimise heat loss.  Before this process is carried out a team of surveyors will determine the position of flues and air vents etc, to ensure the insulation is put in correctly.  At current energy prices, it's estimated that if you live in an average three-bed modern house, cavity wall insulation could save you £115 on your annual energy bills. 

Internal wall insulation

Internal insulation is a good money saver, and if you have fairly generous-sized rooms you shouldn't notice it too much. It involves putting up a frame of vertical timber studs over the wall, filling the space with insulating material, then plaster boarding over it and plastering the new wall. So because your walls become thicker, your room will lose probably a couple of inches. It's a good way of achieving smooth new walls if your existing ones are not in good condition.

Internal wall insulation is crucial to keep the heat in

External rendering

Rendering is another form of external insulation, which also allows you to change the appearance of your house. Rendering involves applying cement, sand and lime plaster to either brick, cement, stone or mud walls, making them thicker and so heat retentive. It's a good option if you live somewhere that takes a battering from rough weather, for example if you live in coastal or hilly / mountainous areas. 

Loft Insulation

We should all have got the message about loft insulation, but as Mike Gideon's experience shows not everyone has.. So lift up your loft hatch and check the situation. Materials used for loft insulation work by preventing warm air escaping through the material. The fibres of matting trap air within it, and for the matting to be fully effective, the weave must not be over stretched or compressed, otherwise the structure trapping the air may be damaged or even destroyed.  Most popular insulation materials include mineral wool Rockwool and sheep's wool product Thermafleece - considered the most eco-friendly option. 

Insulation Grants

Insulation grants are available to UK homeowners. Talk to your local council or call the Energy Saving Trust for details. Find out about grants to help pay for ways of reducing heat loss through windows through the government's Green Home Grants at

And if you're on a low income, read up about the Eco scheme because it could help you with energy saving measures.


Warm air flows out through leaky windows, as anyone with wooden sash windows in a Victorian terrace knows too well, so you can't ignore your windows. Double/triple glazing is effective but expensive, secondary glazing is less expensive but still not cheap. And don't forget that heavy interlined curtains are excellent at insulating windows - and they're cheaper than double glazing - as long as you don't go to Chelsea Harbour Design Centre in London to find your fabric....

Insulation reduces Britain's CO2 emissions

And remember you're not just doing yourself a favour by insulating your home to minimise heat loss, but the environment will benefit hugely too. That's because housing accounts for over a quarter of our greenhouse gas emissions, so by using less energy, we will cut emissions.