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Uninsulated walls are one of the most sinister culprits in homes suffering from soaring energy bills. Responsible for up to a third of your home's heat loss, poorly insulated walls translate to wasted energy, higher bills, and a very uncomfortable living environment.
Fortunately, wall insulation offers a powerful solution that can significantly reduce this heat loss, leading to a warmer home, lower carbon footprint, and substantial financial savings of up to £550 per year in a standard detached house.
By the end of this ultimate guide, you’ll know exactly why wall insulation is one of the most effective home upgrades anyone could invest in. Read on to learn all about a typical house insulation cost, material prices, savings, and government grants that can reduce your costs.
Eager to upgrade your home? Look no further than Household Quotes UK for the best local installers at the best prices! Instead of spending countless hours aimlessly surfing the web and scheduling phone calls, just spend 30 seconds filling out our simple form, and receive up to 3 free home-tailored quotes. No hidden charges, no obligations. Click below to begin!
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Average wall insulation prices for a standard semi-detached UK home sit at around £2,700 for cavity wall insulation, and £7,500 - £13,000 for solid wall insulation, depending on whether it's an internal or external wall job. These prices are lower if you live in a flat, and can be higher with detached houses and bungalows.
Wall insulation is a smart investment, but costs can vary depending on your specific situation, preferences and other factors. Here are some of the main things to consider:
The UK government also offers grant schemes that may significantly reduce your insulation costs. We'll explore these grants in detail later in the article.
Wondering how much is cavity wall insulation? For a typical 3-bedroom semi-detached house in the UK, the average cost of cavity wall insulation is around £2,700. It's important to remember this is just a market average, and the factors discussed earlier can play a big role in quote price changes.
Many UK homes, particularly those built after the 1920s, feature cavity walls. These walls consist of two separate layers – typically a brick outer wall and a concrete inner wall – with an air gap in between. This cavity provides an ideal space for insulation material, significantly improving your home's thermal efficiency.
Here’s a breakdown of general costs for cavity fill insulation per home type, as well as how much you could expect to save annually on your energy bills:
Type of home | Insulation cost (Cavity wall) | Annual energy savings |
---|---|---|
Flat / Apartment | £1,000 | £110 |
Semi-detached home | £2,700 | £235 |
Detached home | £4,600 | £406 |
Mid terrace home | £1,500 | £140 |
Detached bungalow | £2,100 | £175 |
Solid wall insulation can range from £7,500 to £13,000, depending on whether you choose internal or external installation. Internal insulation measures generally tend to be cheaper, but both options are greatly influenced by factors like home size, wall conditions, and installation complexity.
Built before the 1920s, solid walls are indeed charming for homes and properties, but often lack the benefit of modern insulation measures, leading to drafty winters and high energy bills. Solid walls also lack a cavity space, which means that insulation material can only be secured internally or externally. This in turn makes it a more expensive process than cavity walls.
While solid wall insulation carries a significant upfront cost, the long-term benefits are undeniable:
Remember, a professional assessment is key. A qualified installer can provide a tailored quote considering your specific property and needs, helping you make an informed decision for a warmer, more energy-efficient home.
The average cost of external wall insulation tends to be on the higher end of the spectrum, costing around £12,000 - £13,000 for a full job, based on estimates from the Energy Saving Trust and the Royal Institution of Chartered Surveyors (RICS).
The process involves securing insulation material directly onto the outside walls of your property. Normally, rigid insulation boards are used given that they are waterproof, robust, and most likely to withstand weathering. The insulation is then covered with render and cladding to prevent moisture and weather damage.
Consulting with a qualified installer is crucial for a precise estimate tailored to your specific property. They can assess your home's size, features, and wall health to suggest the best insulation approaches for your needs.
Internal wall insulation is generally a more budget-friendly option, typically costing around £7,500 for a complete project in a typical semi-detached UK home (according to RICS and Energy Saving Trust estimates).
There are two main methods for internal wall insulation, each with its price range:
Keep in mind that the cost of internal wall insulation most often accounts for a full insulation job. This involves labour and equipment costs, prep work for your home, and other small jobs. However, there are several ways to make sure you save more money:
The UK government is offering insulation grants to help improve home energy efficiencies and domestic carbon footprints across the UK. These grants are part of the country's goal to achieve net zero emissions by 2050 and are designed to assist fuel-poor and energy-inefficient households.
There are two key grant programs currently open, both of which are active until March 2026:
For a full understanding of the requirements you must meet to qualify for a wall insulation grant, consult the official UK government website.
There are a few ways to make your wall insulation project cheaper, the best being to make use of any grant schemes you may be eligible for. With a grant scheme, you could significantly reduce or potentially get full coverage for wall insulation.
Not all is lost for those who don’t qualify for a grant. If you’re handy with tools and have researched, you can consider a DIY installation instead. Mind you, this is only relevant for internal wall insulation but can be up to three times cheaper than hiring a professional.
While the savings of DIY insulation can be tempting, it's crucial to weigh the potential downsides you could face:
When doing a proper risk assessment, a professional installation doesn’t seem all that bad, and can often wrap up to be your most affordable option in the long run! This is because you pay for a proper job that will last you for decades to come.
Here’s how you can land the best deal on professional installers:
Leave cavity wall and external wall insulation to the professionals. These projects require the use of specialized equipment and expertise to tackle a very complex job. Internal walls, however, are a different story.
Internal wall insulation offers a more DIY-friendly approach to boosting your home's insulation for a fraction of the cost of a professional installer.
The approach for internal wall insulation you take will depend on the existing walls in your home. Based on this, you can decide whether to go ahead with dry lining or stud wall insulation:
In any case, it’s strongly advised to work with a professional insulation company, as there will be plenty of bumps in the road and home specifics to consider. Some of these include relocating electrical wires, properly securing insulation, adding a vapour barrier and many more.
Insulating your home can be a hefty investment, but that doesn't mean you have to break the bank. A variety of insulation materials exist, catering to different budgets and needs. Some offer great cost-saving options while still providing impressive heat retention capabilities.
Generally, expensive insulation offers better heat retention. This translates to better energy efficiency, lower energy bills and a more comfortable living space. However, a downside is that these high-performance materials aren't always environmentally friendly, easy to produce, or available in the market.
Take Polyurethan boards for example. While a champion in effectiveness, they can release harmful fumes and toxic chemicals through off-gassing. This makes it a potentially hazardous choice, despite its impressive insulating power above most other materials.
So, how do you find the perfect balance between affordability and performance? For starters, let's take a look at insulation materials used in internal and external wall jobs, and their costs:
Insulation material | Purpose | Average price (per m2) |
---|---|---|
PIR boards | Internal / External | £5 – £15 |
Fibreglass | Internal | £10 |
(EPS) Polystyrene boards | Internal / External | £10 |
Cellulose | Internal | £10 - £12 |
Mineral (Glass) Wool | Internal | £13 - £17.5 |
Cork boards | Internal / External | £17 - £22 |
Sheep wool | Internal | £17.5 - £22 |
Mineral (Rock) Wool | Internal | £18.2 |
Polyurethane boards | Internal / External | £21.5 |
For cavity wall insulation, a different set of materials are used. These are normally blown insulation, polystyrene beads, and polyurethane foam. Let’s have a look at their costs:
Insulation material | Purpose | Average price (per m2) |
---|---|---|
Blown insulation (Mineral wool) | Cavity walls | £13 - £18 |
Polystyrene beads | Cavity walls | £18 - £22 |
Polyurethane foam | Cavity walls | £22 - £26 |
Here's where the good news comes in! Several affordable insulation materials still excel in both heat retention and market availability, making them great choices for your home:
From keeping your wallet full to creating a healthier and more comfortable home, wall insulation is a worthwhile upgrade that will pay off in benefits for decades ahead. Here are just some of the main advantages that make wall insulation worth it:
Eager to start? Let Household Quotes UK set you on the right path. Instead of spending countless hours stuck on websites and phone calls for research and vetting, we can provide you with industry-competitive quote prices tailored to your home specifics from our network of trusted installers.
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For a typical 3-bedroom semi-detached UK house, cavity wall insulation costs around £2,700, external wall insulation costs between £12,000 – £13,000, and internal wall insulation costs around £7,500. The cost of wall insulation can vary depending on factors such as the type of insulation you choose, the size of your home, and installation complexity.
A cavity wall insulation cost typically sits around £2,700 for a semi-detached UK house. Your property size and type, material selection, location and wall conditions will all play a role in your final investment. For a more accurate idea of cavity wall insulation costs for your specific property, consider using an online cavity wall insulation cost calculator. These tools usually require you to input details like your home’s dimensions and location.
An external wall insulation cost generally ranges around £12,000 – £13,000 for a semi-detached UK property. To get a more accurate idea of the cost for your specific property, it’s recommended to get quotes from several professional installers. They can assess your property and provide a tailored estimate suited to your property.
Several factors come into play, but generally, insulation grants target households with lower incomes, homes with EPC ratings of D or below, or those receiving specific government benefits. To get the most accurate details on eligibility and available grants, check the official UK government portal.
Akif has a keen interest in green home improvement solutions and the role of digital media in identifying climate trends. He aims to provide a multidisciplinary approach to content rooted in credible research and accuracy.