Internal wall insulation could cut your heating costs considerably, and make your home more comfortable.

If your home was built before the 1920s, its external walls are probably solid walls rather than cavity walls.

Solid walls have no gap, so they can’t be filled with cavity wall insulation
cavity walls are made of two layers with a small gap or ‘cavity’ between them
Solid walls can be insulated through – either from the inside or the outside. This will cost more than insulating a standard cavity wall, but the savings on your heating bills will be bigger too.

Work out your wall type
If you have solid walls, then they’re almost certainly not insulated – but the first thing you need to find out is what sort of walls you have.

If you can see the brickwork on the outside of the house, look at the pattern of the bricks as this can show how the wall has been built.

Solid wall
If your home has solid walls, the bricks will have an alternating pattern, with some bricks laid across the wall so you can see the smaller ends from the outside.

Internal insulation can be fitted when you’re planning to redecorate anyway or to fit a new kitchen or bathroom. You can also spread the cost by tackling one room at a time.

Internal wall insulation is done by fitting rigid insulation boards to the wall, or by building a stud wall filled in with insulation material such as mineral wool fibre.

Internal insulation:

• is generally cheaper to install than external wall insulation
• will slightly reduce the floor area of any rooms in which it is applied (the thickness of the insulation is around 100mm)
• can be quite disruptive, but can be done room by room
• requires skirting boards, door frames, and external fittings to be removed and reattached
• can make it hard to fix heavy items to inside walls – although special fixings are available

cannot be done before fixing any problems with penetrating or rising damp

ECO4 is backed by large and medium energy suppliers. They have legal obligations under the Energy Company Obligation (ECO) scheme. This includes companies like British Gas, EDF Energy, E.ON, Scottish Power, and Octopus Energy.

For more information please go to the government’s Ofgem website. 
Ofgem Eco