Answer these simple questions and we will find you the BEST prices
Which type of solar quotes do you need?
Get Free quotes from insulation specialists near you
Save money by comparing quotes and choosing the most competitive offer
The service is 100% free and with no obligation
What Materials Are Used for External Wall Insulation?
- An uninsulated external wall can result in up to 35% of heat being lost.
- Choosing the right external wall insulation material can result in your saving up to £700 on energy bills a year.
- The most cost-effective external wall insulation material is EPS boards whereas PIR boards are the most efficient in reducing energy consumption.
With over 21 million homes in the UK lacking adequate insulation and up to 35% of heat being lost through walls, proper wall insulation is more important than ever. Installing external house insulation can significantly reduce energy costs, potentially saving homeowners between £140 and £700 annually, depending on the type of home and location. It can also lower carbon emissions by 410 to 2,100 kg of CO2 each year, making it a critical step toward a more sustainable lifestyle.
However, the success of external wall insulation hinges on choosing the best external wall insulation material. The right external wall insulation material can balance several factors, including cost, durability, thermal efficiency, and sustainability. Opting for the best external wall insulation material ensures energy savings. It helps protect your home from structural damage and moisture-related issues.
This guide will explore the most common external wall insulation materials, their benefits, and how to choose the best option for your home. By understanding the features and advantages of each material, you can make an informed decision and take an important step toward a more energy-efficient and eco-friendly home.
Ready to choose the best external wall insulation material for your home? Let GreenMatch take care of the research and vetting for you. Instead of wasting hours searching websites and booking appointments with installers, fill out our quick 30-second online form. We’ll send you up to four free quotes from professional installers in your area. Click below to get started!
- Describe your needs
- Get free quotes
- Choose the best offer
Types of external wall insulation
There are many different materials used for insulation that are suitable for external wall insulation, each with distinct advantages and disadvantages based on factors like sustainability, cost, durability, and breathability.
- Polyisocyanurate (PIR) boards: Highly thermally efficient (R-value 5.6–7 per inch), fire-resistant, and easy to install. However, PIR insulation is not moisture-resistant and can lose effectiveness in colder climates.
- Extruded polystyrene (XPS) boards: Known for durability and moisture resistance, with an R-value of 5–6 per inch. However, it is flammable and requires a fire-retardant treatment. It is also one of the more expensive options.
- Expanded polystyrene (EPS) boards: A budget-friendly option with an R-value of 4–4.5 per inch. Easy to install, but flammable and less thermally efficient compared to PIR or XPS.
- Mineral (rock) wool: Offers fire and water resistance, plus durability. However, it is heavy, costly, and can be hazardous to skin and lungs if protective gear is not used.
- Wood fibre: Breathable, making it ideal for single-skin homes. It allows moisture to escape while offering fire resistance. However, it has a low R-value of 3.5 per inch, reducing thermal efficiency.
- Cork boards: Made from renewable cork oak bark, cork is sustainable, biodegradable, and fire-resistant with an R-value of 3.7 per inch. It’s eco-friendly but slightly less thermally efficient.
Cork boards are the most eco-friendly external wall insulation material because they are made from the bark of renewable cork oak trees, which can be harvested without harming the trees. Cork is biodegradable, recyclable, and has a low environmental impact. Additionally, it offers natural fire and water resistance, making it a sustainable and effective insulation option.
In addition to insulation materials, it's important to consider the type of render you will use. Below are external wall insulation render available:
- Cement: Durable and cost-effective but prone to cracking and increases wall thickness.
- Acrylic: Thin, elastic, and versatile but expensive and prone to mould.
- Silicone: Water-resistant, breathable, and self-cleaning, but costly and unsuitable for DIY.
- Lime: Eco-friendly and breathable, ideal for historic buildings, though less weather-resistant with a longer curing time.
How much do external wall insulation materials cost?
External wall insulation cost for a typical three-bedroom terraced house ranges between £3,000 and £5,500. Insulation materials generally make up 40 to 60% of this cost. To stay within your budget and choose the best material, it’s essential to consider these costs. Below are the material costs per m2:
| Material | Average cost per m2 |
|---|---|
| EPS boards | £10 |
| PIR boards | £12.50 |
| Mineral (Rock) wool | £18.20 |
| Woodfibre | £19 |
| Cork board | £19.50 |
| XPS boards | £21.50 |
Labour costs make up a significant part of the overall expense. Labour typically costs around £250 per person per day, with most projects needing two workers. Installation usually takes 5 to 8 days, depending on the complexity.
The material you choose plays a key role in influencing labour costs—materials like PIR boards, which are easier to install, can shorten installation time and lower labour expenses. Daily labour billing per worker means the project's duration directly affects the final cost.
Once you've selected your external wall insulation material, it's also crucial to consider the rendering finish and its associated costs. Below are the costs for different external wall insulation renders:
| Material | Cost per m2 |
|---|---|
| Cement render | £10 per m2 |
| Acrylic render | £30 per m2 |
| Silicone render | £50 per m2 |
| Lime render | £20 per m2 |
Finding the right external wall insulation material that fits both your budget and needs is crucial, and working with trusted specialists is key to a successful project. GreenMatch makes this process easy by connecting you with top specialists in your area. Fill out our quick 30-second form to receive up to four free quotes—no hidden costs, no obligations. Click below to learn more.
- Describe your needs
- Get free quotes
- Choose the best offer
What is the best external wall insulation material?
When choosing the best external wall insulation material, it's essential to balance factors like budget, thermal efficiency, breathability, durability, and sustainability. Here's a summary of the top options:
- Best for budget: EPS boards are the most affordable option, costing around £10 per m², offering decent insulation at a lower price point.
- Best for thermal efficiency: PIR boards provide the highest R-value (5.6 to 7 per inch), making them the most thermally efficient choice for insulation.
- Best for breathability: Wood fibre insulation is perfect for homes that require breathability, such as stone buildings, as it allows moisture to escape, preventing dampness and protecting the structural integrity of your walls.
- Best for durability: XPS boards are known for their durability and moisture resistance, ideal for areas exposed to mechanical stress. It can last up to 50 years, making it a worthwhile investment,
- Best for sustainability: Cork boards are the most eco-friendly choice. Made from the renewable bark of cork oak trees, cork is biodegradable, recyclable, and naturally fire- and moisture-resistant
Choosing the right external wall insulation is essential, ensuring it suits both your needs and your home’s structure. Problems with external wall insulation can occur if you select a material that isn’t breathable for stone walls or adds excessive weight to a weakened wall.
That’s why it’s vital to collaborate with a professional insulation specialist. An expert who understands both your preferences and your home’s specific requirements can help you avoid issues such as structural damage or condensation. To ensure you choose the right insulation, GreenMatch offers up to four free quotes from top specialists. Just fill out our 30-second form to get started!
- Describe your needs
- Get free quotes
- Choose the best offer
FAQ
We strive to connect our customers with the right product and supplier. Would you like to be part of GreenMatch?
- Describe your needs
- Get free quotes
- Choose the best offer