9 Best Types of Roof Insulation for UK Homes

Keeping your home warm, energy-efficient, and protected from rising energy bills starts with good insulation—especially in your roof.

Did you know that around 25% of a home’s heat escapes through the roof? That’s why choosing the right roof insulation material isn’t just smart—it’s essential.

At Roofing Newcastle, we’re often asked: What’s the best type of roof insulation for UK homes? The answer depends on your property, your budget, and whether your loft is used for storage, converted into a room, or left untouched.

In this guide, we’ll walk you through the 9 best types of roof insulation used across the UK. We’ll explain what they’re good for, how they’re installed, and what kind of home they’re best suited to.

Let’s jump in.

Why Roof Insulation is Important

Roof insulation is a crucial aspect of maintaining a comfortable and energy-efficient home. Proper insulation can have a significant impact on reducing heat loss, lowering energy bills, and preventing condensation and moisture damage.

Reduces Heat Loss and Energy Bills

A well-insulated roof can help reduce heat loss by up to 25%, which can lead to significant savings on energy bills. In fact, according to the UK’s National Insulation Association, a properly insulated roof can save homeowners up to £230 annually on energy bills. By reducing heat loss, roof insulation can also help reduce the strain on heating systems, leading to a longer lifespan and lower maintenance costs.

Prevents Condensation and Moisture Damage

Roof insulation can also help prevent condensation and moisture damage by reducing the temperature difference between the inside and outside of the roof. This can help prevent the formation of condensation, which can lead to mould, mildew, and structural damage. By keeping the roof space dry and well-ventilated, roof insulation can help prevent costly repairs and maintain the integrity of the roof structure.

Increases Comfort and Property Value

Proper roof insulation can also increase the comfort and value of a property. By reducing heat loss and preventing condensation, roof insulation can help maintain a consistent indoor temperature, making the home more comfortable and livable. Additionally, a well-insulated roof can also increase the value of a property, making it more attractive to potential buyers.

1. Blanket Insulation (Loft Roll)

This is the most common form of insulation in the UK—and for good reason.

Blanket insulation usually comes in rolls made from:

• Mineral wool
• Glass wool
• Sheep’s wool

It’s laid between the joists on the floor of your loft and sometimes in a second layer across the top. Different types of roof insulations can provide varying levels of thermal efficiency and cost-effectiveness.

Best for: Unconverted lofts used for storage. Pros: Cheap, easy to install, widely available. Cons: Not suitable for insulating roof slopes in loft conversions.

2. Rigid Foam Boards

A well-insulated roof using the right insulation material can help reduce heat loss by up to 25%. Foam boards—like PIR (Polyisocyanurate) or phenolic boards—are popular for their high insulation value in a thin layer.

They’re commonly used between roof rafters, especially in loft conversions or warm roof systems.

Best for: Converted lofts or warm roofs. Pros: Very high thermal performance, moisture resistant. Cons: More expensive, needs accurate cutting to fit snugly.

3. Multifoil Insulation

This modern insulation type is made of several layers of foil and foam or wadding. Materials like foam plastic insulation can be particularly effective in reducing the temperature difference between the inside and outside of the roof. It’s thin, reflective, and excellent at bouncing heat back into the home.

Multifoils are often used in combination with other insulation types.

Best for: Loft conversions or homes where space is tight. Pros: Thin, lightweight, easy to install. Cons: Usually needs to be paired with other insulation to meet UK building regulations.

4. Blown-In Insulation

This type involves loose-fill material—like cellulose or mineral wool—being blown into the roof space using a specialist machine. Mineral wool insulation is known for its excellent thermal and acoustic properties, making homes more comfortable and valuable.

It’s ideal for filling small or awkward spaces that rolls or boards can’t reach.

Best for: Older properties or irregular lofts. Pros: Fast to install, great for hard-to-reach areas. Cons: Needs a professional installer, can settle over time and reduce performance.

5. Spray Foam Insulation

Spray foam (usually polyurethane) is applied as a liquid and then expands to fill gaps and form a solid insulating layer.

It can be applied to the underside of the roof deck in lofts or between rafters.

Best for: Homes with hard-to-insulate roofs, or those looking for airtightness.
Pros: Excellent air sealing, very effective insulation.
Cons: Expensive, can complicate future roof repairs or affect mortgage eligibility in some cases.

6. Sheep’s Wool Insulation

This eco-friendly option is gaining popularity in UK homes. It regulates moisture well and is safe to handle.

Sheep’s wool comes in rolls or batts, and performs well thermally while also helping regulate indoor humidity.

Best for: Eco-conscious homeowners or breathable roof systems.
Pros: Sustainable, naturally breathable, great acoustic insulation.
Cons: More expensive than synthetic materials.

7. Warm Roof Insulation

A warm roof involves placing insulation above the roof deck, just under the waterproof layer, instead of between the rafters.

It’s commonly used in flat roofs and modern builds.

Best for: Flat roofs or new roof installations.
Pros: Prevents cold bridging, keeps loft space warmer.
Cons: More complex and costly than standard loft insulation.

8. Cold Roof Insulation

This traditional method places insulation between the ceiling joists of the top floor, allowing the loft space to remain unheated.

It’s the opposite of a warm roof and suits unconverted lofts.

Best for: Standard pitched roofs with unused lofts.
Pros: Affordable and simple to install.
Cons: Doesn’t heat the loft space—pipes and tanks may need lagging.

9. Reflective Foil Insulation Boards

There are various types of roof insulation material available, each with its own unique benefits and characteristics. These boards combine traditional insulation materials like PIR with reflective foil facings that bounce radiant heat back into the home.

They’re often used in timber-frame properties or extensions.

Best for: Roofs with limited space or projects where radiant heat control is needed. Pros: Thin profile, high performance. Cons: Costlier than traditional wool or rolls.

Insulation Materials

There are various types of insulation materials available, each with its own unique benefits and characteristics. Some of the most common types of insulation materials include:

Polyisocyanurate (PIR) Board

Polyisocyanurate (PIR) board is a type of rigid foam insulation that is commonly used in flat roof applications. It is made from a combination of polyisocyanurate and polyurethane, which provides excellent thermal insulation and durability. PIR board is also resistant to moisture and can be used in a variety of applications, including flat roofs, pitched roofs, and walls. It is a popular choice among builders and homeowners due to its high R-value, ease of installation, and affordability.

Which Roof Insulation Is Right for You?

That depends on a few key questions:

• Is your loft converted or unconverted?
• Do you want to use the loft as a room or just for storage?
• Are you retrofitting or planning a new roof installation?
• What’s your budget?
• Are you looking for a sustainable or high-performance option?

At Roofing Newcastle, we help homeowners across the North East find the right solution based on the structure and purpose of their roof space.

We also make sure your insulation meets all UK Building Regulations, so your home is compliant and as energy-efficient as possible.

How Much Does Roof Insulation Cost?

Here’s a rough guide:

• Blanket rolls: £5–£10 per m²
• Rigid boards: £15–£25 per m²
• Multifoil insulation: £20–£40 per m²
• Spray foam: £40–£70 per m²
• Blown-in insulation: £15–£30 per m²

Installation costs vary based on access, complexity, and whether other roof work is being done at the same time.

We offer full pricing transparency at Roofing Newcastle and provide free quotes across the region.

Final Thoughts

Choosing the right type of roof insulation is one of the best things you can do for your home.

It cuts energy bills, keeps your house warm in winter and cool in summer, and adds long-term value to your property.

With so many insulation options available, it can be hard to know what’s best—but you don’t have to figure it out alone.

Get in touch with Roofing Newcastle today for honest advice, expert installation, and the kind of service that puts your home first. Whether you’re renovating your loft or planning a full reroof, we’ll help you choose insulation that performs—and lasts.