Solid wall insulation

Houses built before 1920 normally won’t have a wall cavity to fill, however you may still benefit from solid wall insulation.  

Whether you have it fitted internally or externally, solid wall insulation helps to keep the inside temperatures up and your costs down, especially when you consider that solid walls let through more heat than cavity walls do2.

If your home is built using timber or steel, rather than bricks then the insulation will be different, but it could still be done and you can find out more from The National Insulation Association (NIA).

Putting a home improvement loan to the best use

Insulating your solid walls can help make savings on your fuel bills.  Depending on the type of property you live in, the Energy Savings Trust indicates that you could save between £145 and £4552 on your annual fuel bill, so if you are considering a home improvement loan for anything else, such as a loft conversion, extension, or conservatory, you may want to consider  adding insulation to your budget if it helps towards saving you money in the long run. Insulating your solid walls may be cheaper  to do if you’re having other work done externally, such as a new roof, solar panels or even painting the windows if for example, you already have scaffolding up .

…and the best materials to use?

And if you’re wondering whichtype of insulation to use, you may want to consider breathable or vapour permeable, which allow continuous movement of air and this helps reduce any possibility of moisture build-up. If however, you install non-breathable or vapour impermeable solid wall insulation materials, then we recommend you ask the installer about actions you may need to take to prevent the build-up of moisture.

Your installer should also confirm whether the installation is covered by a warranty or that any products used are covered by a guarantee.

Relevant bodies to check out are:

Roof, Loft and Floor Insulation

It’s not just the walls that can let heat escape. Uninsulated floors, lofts and roofs can all bring a little chill to your home by letting heat escape and increasing your fuel costs.

As heat rises, your loft and roof are particularly vulnerable to escaping heat. Good insulation can help you stay energy efficient from top to bottom, keeping that warmth where it belongs and saving up to £240 a year3. As part of your home improvement loan budget, it could be money well spent, particularly given that loft insulation can last up to 42 years and pay for itself many times over according to the Energy Saving Trust3.

Loft insulation and getting it right

So long as your loft is easily accessible and you have no damp problems, then you may be able to do this yourself.  Do however, check whether you need any additional ventilation or building control approval. 

If you use for storage, a professional could  lay boards over your joists making it easier for you to move around and to store your belongings. If you only insulate the joists before laying boards, it may not be thick enough to do a proper job of keeping you cosy – and reducing your ful bills. A professional may approach the task by insulating your loft with mineral wool as normal then laying rigid insulation boards on top. Another option is to raise the level of the floor so you can fit enough insulation beneath the new floor level, however a professional should be able to guide you as to which is the best solution for your needs.

Best practice up on the roof

Should you  want to convert your loft into a fully functioning living space, you may consider insulating your roof rather than the floor. Rigid insulation boards can do the job nicely, fitted neatly between your rafters. Plasterboard is then laid over the top and a good plasterer could skim over the top like no one had ever been there.

Insulating your floors

You could save around £40 to £85 a year by insulating your floors4, including sealing the gaps between floorboards and skirting boards. You may even notice an extra level of cosiness as those draughts get plugged up one by one.

Older homes may have suspended wooden floorboards, which can be insulated by lifting them and laying the same kind of mineral wool insulation used in lofts. However, if your home is newer, it’s more likely that your floor is solid concrete. That doesn’t mean you may not have an opportunity to save energy – and money – though; flooring can be insulated at the same time as it’s being  replaced or you can lay rigid insulation over the top of it.

One thing to bear in mind if you are including floor insulation as part of any home improvement, is that whilst you don’t need to insulate floors of upstairs rooms above already heated spaces, it’s worth considering insulating floors above unheated spaces like garages, as these can lose a lot of heat.

Give your floors room to breathe

Lastly, a quick tip from us all is to check where your airbricks are located before you go full steam ahead and insulate your floors. That’s because floorboards can rot without adequate ventilation so make sure you don’t block any airbricks which lie below floors in your outside walls.

Because insulating walls, floors and your roof can be great ways to save energy, keep your home much cosier and save you money in the long run, it’s well worth including these cost-effective jobs as part of any bigger ideas you have.

Cavity wall insulation

Homes without insulation lose around a third of their heat through the walls1 therefore cosy evenings in uninsulated homes could end up costing more than they should.

With the right insulation, you could keep everyone comfortable and save up to £160 a year1 on your heating bills for a typical house.

But how do you know if your wall has a cavity? Well, as a general rule, if your house was built after the 1920s, it’s likely to have cavity walls – two separate walls with a gap in between. Also worth knowing is that most houses built from the 1990s onwards will have some form of wall insulation to keep the heat in – however, if your plans include a conservatorya loft conversion  or an extension, you’ll need to consider your insulation options whether you live in an older or much newer house.

What type of walls have you got?

You can of course, take advice on what type of walls you have, but it’s possible that you may be able to find out yourself.  Looking at the brickwork from the outside of your home and noticing a regular pattern from top to bottom usually suggests you’re likely to have cavity walls. But if you notice irregular brickwork, such as seeing longer lengths of brick interspersed with shorter, end of bricks as though they are criss-crossing each other normally indicates  a solid wall. If you’re unsure, it’s always worth asking a builder or a wall insulator for advice, or you can use the Energy Saving Trust’s Home Energy Check tool which can help you work out what sort of walls you have.

Is it worth insulating your cavity wall?

Every time you heat a home with cavities which aren’t filled, you’re effectively heating the great outdoors. According to the Energy Savings Trust, depending on the size and type of your property, you may be able to save between £90 and £275 a year on fuel bills1. So with installation costs generally around anything between £330 and £7201, it’s easy to see how you can recoup your costs relatively within a few years.

Cavity walls - things to consider

Can you get access to your external walls? Cavity wall insulation is blown into the space from the outside of your house so it’s important that the installer advises which areas they will need to access.

And you need to check if those walls are in good shape – especially internally. If you have damp patches on your internal walls, we recommend you don’t insulate your walls until you have had any damp problems investigated as these may need to be resolved first.   A good builder or a specialist in damp prevention can help you with this.

Get a recommended installer. As with all these types of project, a good recommendation from someone you know and trust goes a long way. On top of that, you should check for a trusted installer, who is certified by a recognised source such as:

It’s also worth checking your installer is signed up to a code of professional practice such as those provided by the NIA and that your insulation is guaranteed appropriately.