Insulating your solid walls 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 can be insulated though – 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.
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.
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.
If your home has cavity walls, the bricks will usually have an even pattern with all the bricks laid lengthways.
If the brickwork has been covered, you can also tell by measuring the width of the wall. Examine a window or door on one of your external walls.
If you live in a house that has a non-traditional construction such as a concrete, steel or timber-framed building, you will need a specialist installer with experience in insulating your building type to advise you on your options.
Typical installation costs* of solid wall insulation can vary as follows:
*Based on a typical semi-detached house in Great Britain
You might be able to reduce these costs by carrying out the work at the same time as other home improvements or by not tackling the whole house at once.
The costs we suggest for installing solid wall insulation are for paying a company to come in, insulate your whole house in one go, fully redecorate and replace everything just as it was. Some people want exactly this, but it does cost a lot of money.
If you’re looking to spend less, it is advisable to insulate a wall when you are having other building or decorating work done.
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.
External insulation will also cost less if you fit it when you’re having other work done to the outside. If you’re having a new roof, or painting the windows, or even having solar PV panels fitted, then you will probably have scaffolding up already, which can save a bit on the costs. If your walls need repointing or other repair work, it’s worth getting a quote for a complete refurbishment including insulation – it will probably work out cheaper than doing the two things separately.
Sometimes there is financial support available to help with the cost of solid wall insulation.
The Green Homes Grant, available to householders in England covers a range of home energy efficiency measures, including insulation.
You can contact your local authority to see if there is any help in your area, or read about financial support in Scotland.
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:
Find out more about choosing internal wall insulation.
External wall insulation involves fixing a layer of insulation material to the wall, then covering it with a special type of render (plasterwork) or cladding.
The finish can be smooth, textured, painted, tiled, panelled, pebble-dashed, or finished with brick slips.
External insulation:
Find out more about choosing external wall insulation.
In traditionally built properties with solid walls, water vapour can usually move quite freely through the building. This is partly because of the high levels of ventilation and draughts, but also because water vapour can travel through the bricks and stones that the walls are made of. When you insulate an older building, you will change the way that water vapour behaves in several ways:
Whenever you fit solid wall insulation to a building you need to take account of water vapour to make sure that you don’t create new damp problems in the future. This may involve using “breathable” insulation materials that will allow the vapour to carry on permeating the walls, or it could involve creating a continuous vapour barrier to make sure no vapour can get into the walls from the inside. You will need an experienced specialist installer to develop a moisture control strategy that is specific to your building.
You should check with your installer that the installation is covered by an appropriate 25 year guarantee. They may be members of the SWIGA guarantee scheme, or they may offer an independent insurance-backed guarantee. You can find a list of Ofgem approved guarantee schemes.
The new Green Homes Grant scheme helps fund two-thirds of the cost of energy saving home improvements in homes across England.
BlogWe take a look at the financial help available to help improve energy efficiency in the home.
BlogIf you are faced with damp problems due to a botched insulation installation job, what can you do about it?
