Best Cavity Wall Insulation for Old Houses: Complete 2024 Guide

While newer homes have better insulation, older houses (over 25 years) may not be quite as fortunate. This can lead to significant heating inefficiencies and lower home value. While not all houses are suitable for insulation, some can certainly benefit from it. Let’s examine the best methods of wall cavity insulation and when it is appropriate for older properties.

If you’re looking to insulate your house, it’s best to have it properly assessed since each one has different needs. A reliable installer will give you the best prices and get you the right insulation materials. Rather than wasting days looking for the right professional, why not let us take the guesswork out of your search?

Instead of laboriously calling up companies, all you have to do is fill out a simple 30-second form. We’ll get you the best prices from up to 3 reliable installers in your area. Click the button below to get started.

The best form of cavity wall insulation in old houses is mineral wool or polyurethane, depending on the type of installation. Mineral wool is great if you have the option of removing the wall or panelling, while polyurethane is ideal for less intrusive projects as it can be poured through holes in a wall. Generally, they both allow for adequate protection against the cold and decreased heating costs.

Which insulation material homeowners end up choosing may come down to how extensive their repair plans are. While mineral wools and natural fibres are better for extensive renovations, this may not be appropriate for all older homes. For more subtle repairs, polyurethane is a better way to go as it is a foam mixture.

Insulation carries other benefits as well. Cavity wall sound insulation improves soundproofing as it fills internal gaps and reduces noise transfer. Rockwool and similar materials absorb sound, while installing rigid panels can ensure complete cavity filling for effective noise reduction.

Mineral wool consists of yarn made from melted glass (glass wool) or stone (rock wool). It is spun and threaded together to form wool-like sheets or batts that can be inserted into wall cavities or inserted as mineral fibres. It can be blown into the walls like foam. Mineral wool made from stone is preferable to fibreglass as it has fewer health hazards to pose and is less prone to condensation (which can be an issue in older properties).

The reason it rests as a top choice for old homes is that it is far more effective at creating breathability and letting out moisture build up while being easy to install. Old homes are designed in such a way that they often have draughts, especially if they have a loft. The extra breathability comes in handy here, as experts state that it can let vapour pass and prevent degradation.

Natural fibres like Sheep wool can be great in many situations where mineral wool won’t do. For one thing, it’s better to install around wood and timber elements like walls, columns, infrastructure, etc. This can prevent mould build-up and stop the wood from distorting.

Much like mineral wool batts and slabs, sheep wool comes in large chunks and won’t fit through drilled holes. This means they are better for either new constructions or extensive wall renovation. This would be best for a larger-scale renovation where a significant portion of the wall can be removed.

Polyurethane foam is one of the most common building materials used for insulation. Used in many different products, its popularity can be attributed to its versatility and higher thermal resistance. These same characteristics make it a viable material for old homes.

Aside from insulating against heat, polyurethane is also great for noise reduction (when compared with other plastic insulation materials). This can come in handy for old homes as they may have soundproofing issues.

If you’re not sure what material would work best for you, we recommend contacting an installer. A reliable installer can advise you on the best methods and materials while providing quick and easy installation of cavity wall insulation. However, it can be difficult to compare their rates on your own as it can be a hassle that requires compiling prices and vetting companies on your own. That’s why our service is quicker and easier.

We have a network of installers we’ve personally vetted to ensure top-of-the-line service. All you need to do is click the button below, fill out a 30-second form, and we’ll provide you with up to 3 free quotes with no payment obligations.

Cavity wall insulation costs in the UK are generally between £1,000 and £4,600 depending on the type and size of the the property. Cavity wall insulation costs for a 3-bed semi will be around £2,700. Annual savings can range from £110 to £405 with payback periods between 9 to 12 years in England, Scotland, and Wales.

*This data is from Energy Saving Trust, April 2024. For more accurate prices, get a local installer QUOTE now!

While the figures above cover costs for England, Scotland, and Wales, the cost of wall cavity insulation in Northern Ireland can vary.

As is evident from the data, insulation costs in Northern Ireland vary wildly from other countries. With costs as low as £506 to £1,300, the payback period can be 3 to 4 years. Conversely, savings can be even higher, going up to £520.

*This data is from Energy Saving Trust, April 2024. For more accurate prices, get a local installer QUOTE now!

The discrepancy in prices can be attributed to the lower price of insulation in the region. Savings can also be higher in Northern Ireland because many homes heat with oil boilers which are often very inefficient. Therefore, with proper insulation, there is more of an impact of keeping in heat.

So, how long does cavity wall insulation last? Experts estimate an average of 25 years, which is more than twice its break-even point. You can continue reaping the benefits of insulation for at least a decade past that point.

If prices are a concern for you, there are government plans and incentives that can help improve your home. Grants for insulation include:

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Insulating an old home in the UK should be done with caution as not all homes are suitable for it. If your home can accommodate insulation, it can be worth it as it can save up to £405 per year. Insulation can be an effective energy-saving measure that is cheaper and less intrusive than changing your heating system.

Aside from the savings on bills, it also decreases the load on the energy grid while lowering the average home’s carbon footprint by 1,500kg of CO2 per year. This is also why the government offers grants like the ECO4 scheme, which can make insulation more than worth it.

If you’re not sure if your home is viable for insulation, you’ll need the help of a reliable installer. You need to be sure they have your home’s best interest in mind, especially with older homes. Finding one ordinarily takes days of research and frustrating price comparisons and still won’t ensure you’ve found adequate help. That’s why our service is a far better alternative.

All you need to do is fill out a 30-second form and we’ll find you quotes from up to 3 reliable installers in your area. We’ve vetted them personally so you can be sure they are up to the task. Click the button below to get the best prices.