The average cost of roof insulation
is between £400 and £600
Pricing guides

How much does roof insulation cost?

Are you wondering how much roof insulation costs in the UK? Whether you’re hoping to insulate a flat roof or a pitched one, we’re here to share how much you can expect to pay in our pricing guide. Please note, all costs are accurate as of 2024.

Proper roof insulation in your home is essential as it significantly reduces heat loss, keeping you warm and decreasing energy consumption. This leads to lower heating bills and helps lessen your environmental impact by reducing the carbon footprint associated with excessive energy use.

In the UK, the price for insulating your roof can vary widely based on factors like material choices, the size of your property and the type of insulation you opt for. We’re here to provide a clear breakdown of the potential costs involved in roof insulation, helping you budget effectively and make an informed decision. 


Average roof insulation costs

Roof insulation in the UK typically costs between £400 and £600. Labour costs alone are usually £150 to £200 per day per tradesperson. Labour costs typically depend mostly on how long the job will take, which is usually one to two days.

Here’s a table of average prices for the most common roof insulation jobs. Remember, these prices are an average and will likely differ depending on various factors. Before hiring a tradesperson, always discuss costs and request at least three different quotes from several roofers so you can compare.


Type of insulationType of roofArea coveredCost
Fibreglass insulationPitched roof20m2 £380 to £420
Mineral wool rollsPitched room20m2 £400 to £480
Spray insulationPitched roof20m2 £700 to £900
Warm deck insulation boardsFlat roof20m2£600 to £700


Get a free roof insulation quote

We can help you meet professional insulation specialists near you to get real quotes today.

How much does roof insulation cost?

The cost of roof insulation typically depends on various factors, including the extent and area of the project, the type of roof you have and the materials used. In the UK, most homes have a pitched roof consisting of two sloped sides that run downwards, away from the central ridge of the roof. When insulating a house with a pitched roof, typically, two methods can be used.

The insulation material can either be placed above the roof joists or under the slope of the pitch. And the overall cost of your roof insulation project will depend on the method of insulation you use.

Typical materials used for roof insulation include polystyrene insulation panels, which are typically backed with foil and are cut to size. Other options include mineral or fibreglass lagging, held in place with wooden slats and expanded polystyrene products that unfurl to fill the space. Spray foam can also be used for some projects.

Hiring a professional roof insulation expert may seem costly, but professionals ensure correct and efficient insulation, leading to better energy savings and potentially extending the lifespan of your roof. They can also identify and address underlying roof issues, preventing future damage. Additionally, their work often comes with warranties, offering peace of mind and added protection for your investment. For help choosing a tradesperson, have a look at our handy insulation specialist hiring guide.

Loft or attic insulation cost

The average attic or loft insulation cost in the UK is £250 per day for labour costs. The full price for insulating a loft with basic quilt insulation is £670 plus VAT. 

Conservatory roof insulation cost

The average total cost of conservatory roof insulation is £2,600, taking around one to three days. Here are some average prices for various conservatory roof insulation services.


Conservatory sizePlastered insulationUPVC insulation Aluminium panel insulation 
3m x 2m£1,000 to £1,500£900 to £1,100£750 to £1,000
3m x 3m£2,000 to £2,500£1,100 to £1,350£1,000 to £1,100
4m x 4m£3,000 to £3,750£2,000 to £3,250£2,000 to £2,750
6m x 4m£4,750 to £5,000£3,250 to £3,750£2,750 to £3,000
8m x 6m£6,000 to £7,000£3,750 to £5,000£3,750 to £4,000

Flat roof insulation cost

The average flat roof insulation costs between £600 and £700 per 20m2 using warm deck insulation boards. Flat roof insulation typically takes around one to two days to complete.

Warm roof insulation cost

Warm roof insulation costs around £600 to £700 per 20m2  on a flat roof. Warm roof insulation typically takes around one to two days to complete.

Spray roof insulation cost

Spray roof insulation typically costs between £700 and £900 per 20m2  on a pitched roof. Spray roof insulation takes around one to two days to complete.

Roof insulation cost per m2

Here are roof insulation costs per m² in the UK, depending on the type of insulation. Be aware that these are just the supply costs, which don’t include labour fees.


Type of insulationCost per m²
Fibreglass insulation£4 to £6
Mineral wool rolls£5 to £9
Spray insulation £20 to £30
Warm deck insulation boards£15 to £20



How long does roof insulation take?

Depending on the scale and complexity of the job, roof insulation usually takes around one to two days. Here’s how long you can expect roof insulation to take, depending on the type of insulation and roof.


Type of insulationType of roofArea coveredInsulation time
Fibreglass insulationPitched roof20m2One day or less
Mineral wool rollsPitched room20m2One to two days
Spray insulationPitched roof20m2One day or less
Warm deck insulation boardsFlat roof20m2One to two days

How to reduce roof insulation costs

Reducing the cost of roof insulation can be achieved through a combination of smart planning and careful material selection. Here are some tips on minimising expenses while still ensuring effective insulation in your home. 

  • Conduct thorough research and planning: Start by assessing your roof's insulation needs. Consider factors like climate, roof type and existing insulation. This helps in choosing the right insulation specialist for the job as well as the materials and methods, avoiding overspending on unsuitable products. If you’re unsure how to assess your roof, an expert can also help you.
  • Choose cost-effective materials: Opt for affordable, yet effective, insulation materials like fibreglass, cellulose or certain foam insulations. Keep an eye out for discounts or sales at hardware stores and online marketplaces to find quality materials at lower prices. 
  • Try a DIY approach: It’s possible to undertake simpler tasks yourself to save on labour costs. This can include clearing the attic, removing old insulation and preparing the area for new insulation. However, for the actual installation, especially in complex areas, it’s safer to rely on professionals. 
  • Seek professional assistance for complex tasks: For installing insulation in hard-to-reach areas or where specialised skills are required, hiring a professional is essential. They ensure safety and efficiency, which are crucial for long-lasting and effective insulation.




What’s the best insulation for a roof?

The optimal roof insulation choice depends on various factors, such as climate conditions, roof structure and budget considerations. Fibreglass wool is a popular option for colder climates due to its excellent thermal resistance and cost effectiveness. In contrast, mineral wool rolls are favoured in various environments for their fire-resistant properties, sound insulation capabilities and thermal efficiency. Both options are suitable for different requirements and preferences and offer effective insulation performance. Talk to your insulation specialist about which they would recommend.

What does the roof insulation process involve?

The roof insulation process typically involves several key steps. First, the existing roof structure and attic space are assessed to determine the type and amount of insulation needed. Next, the chosen insulation material is prepared and installed.

This installation can involve laying rolls or batts, fitting rigid panels or spraying foam in the attic or between roof rafters. The process must ensure that the insulation is evenly distributed without gaps and that attention is given to sealing air leaks for optimal energy efficiency. Finally, your insulation specialist will make sure that proper ventilation is in place to prevent moisture buildup. This is crucial for the longevity of the roof and the insulation.

How can I tell if my roof insulation needs replacing? 

You can usually determine if your roof insulation needs replacing by looking for certain signs. If your energy bills are unusually high, it could suggest poor insulation efficiency. Check the attic for any visible deterioration, such as dampness, mould or thinning of the insulation material. 

Likewise, uneven temperatures in your home, like cold drafts or hot spots, are also indicators of inadequate insulation. Lastly, if your insulation is several decades old, it may not meet current energy efficiency standards and could benefit from an upgrade. If you’re unsure, regular inspections by a professional can be helpful.


Your roof insulation checklist

Even if you’re hiring a professional for roof insulation, it’s essential to be prepared. Here’s a handy checklist to tick off before hiring an expert roofer.

  • Do your research and request quotes from various professional tradespeople in your area. We recommend sourcing at least three to compare costs and services.
  • Check that the tradesperson you choose is qualified and experienced to carry out the job.
  • Speak with your chosen tradesperson about the methods of insulation and materials they recommend for your project. 
  • Be sure not to pay the total cost for your project up front, and always request a written cost breakdown. If a deposit is required, make sure you receive proof in writing of any communications and transactions, including the final price.

Finding a professional roof insulator is free, easy and quick with MyBuilder. Simply post the details of your project on our platform, and anyone available, qualified and interested can reach out.


Get a free roof insulation quote

We can help you meet professional insulation specialists near you to get real quotes today.

Roofing costs

Roofing costs

How much does a new roof cost?

Loft insulation costs

Loft insulation costs

How much does loft insulation cost?

Loft conversion costs

Loft conversion costs

How much does a loft conversion cost?

View more pricing guides