What is External Wall Insulation?

Designed for homes with solid walls that typically lose heat, by applying insulation to the exterior of your home, it effectively enhances both comfort and energy efficiency.

Understanding external wall insulation

Applied to homes typically built before the 1920s, it involves fitting insulation material to the outside walls and then covering it with a special type of render or cladding.

This method not only improves thermal performance, reducing the amount of heat lost through walls, but also can transform the external appearance of your property. It significantly improves warmth and energy efficiency while potentially increasing the home's value.

External wall insulation is suitable for solid brick or stone homes, often pre-1920s, but it’s also offered where cavity wall insulation isn’t possible or enough.
Let’s walk through costs, materials, the installation process, and the most common questions you might have about external wall insulation.

External wall insulation

Existing external wall

Adhesive

Insulation board

Made of expanded polystyrene (EPS), mineral wool, or polyurethane foam, it’s bound using fixings anchors.

Reinforcing mesh

Made of fiberglass or similar material, it provides additional strength and durability to the insulation system.

Render base coat

Render finishing coat

Key benefits of wall insulation

Energy efficiency

By reducing heat transfer through the walls, it can lower heating and cooling costs.

Condensation control

By increasing the wall’s temperature, it minimises condensation, dampness, and mould growth.

Noise reduction

The added insulation acts as a sound barrier, creating a quieter home environment.

Increased property value

Besides saving money on utility bills, it but can also make the property more appealing to energy-conscious buyers.

Frequently asked questions

Who are the best wall insulation installers?

The best wall insulation installers are those with experience, training, and proper accreditation. We only work with installers who are members of reputable trade associations and have positive customer reviews regarding their service, quality, and pricing.

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How much does external wall insulation cost?

The cost can vary depending on factors such as the size of your home, the materials used, and the complexity of the installation. Prices typically range from £ 8,000 — £22,000 for an average-sized home. However, this investment often pays for itself over time through significantly reduced heating bills.

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What are the disadvantages of external wall insulation?

Initial cost

It can be a significant investment upfront, although it is often offset by long-term energy savings and potential grants.

Installation disruption

The installation process may cause some inconvenience, as it takes place on the building’s exterior.

Planning permissions

In some cases, planning permission may be required, especially for listed buildings or homes in conservation areas.

Maintenance

Over time, the external finish may require occasional cleaning or maintenance to retain its appearance and performance.

What are some external wall insulation problems?

Poor installation

If not installed correctly, External Wall Insulation can lead to issues such as cold bridging, dampness, and reduced insulation performance.

Water ingress

If the external finish or sealant is damaged, water may penetrate the insulation system, causing dampness and reducing the insulation’s effectiveness.

Structural issues

In rare cases, adding it may exacerbate existing structural problems or create new ones if not properly assessed and addressed before installation.

Aesthetic concerns

Some homeowners may not like the appearance of External Wall Insulation, particularly if it changes the property’s original character.

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