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Installing loft insulation can averagely cost around £930 for a semi detached home. However, the cost of insulating your loft depends on the choice of insulation material, area, and availability of loft insulation grant.
However, the cost of loft insulation is worth it as installing only 10cm of loft insulation can reduce the heat loss (heat escaping through the loft) by 75%. In this article, we will explore the loft insulation costs per square meter and the impacts of insulation on energy costs.
Before we dig deeper, here are the key takeaways:
- Insulation costs for your loft can start from £125 and go up to £4,125 (depending on insulation material, labour costs, and other factors.
- The recommended insulation thickness for loft insulation is 270mm by the government to achieve a U-value of 0.15 watts.
- Loft insulation can save up to £115 to £215 per year on energy costs.
How Much Does Loft Insulation Cost in 2025?
The cost of insulating a loft depends on the type of insulating material (cellulose insulation, mineral-wool, rigid insulation, or wool insulation) , the size of your home, the loft space, and the ease of installation.
The costs also depend on other factors like whether you are installing the insulation through DIY or hiring the labour. Type of loft insulation materials like loose-fil insulation or spray foam insulation requires professional installation.
| House size | Blanket insulation | Loose-fill insulation | Sheet insulation | Blown fibre insulation |
|---|---|---|---|---|
| Terraced | £125–£160 | £180–£225 | £250–£310 | £1,375–£1,720 |
| Semi-detached | £200–£250 | £290–£360 | £400–£500 | £2,200–£2,750 |
| Detached | £300–£375 | £430–£540 | £600–£750 | £3,300–£4,125 |
| Bungalow | £375–£420 | £700–£730 | £1,000–£1,200 | Around £3,588 |
Insulation costs may vary if you need to remove the existing insulation as well.
Cost of Loft Insulation Materials per M2
For more precise estimates, you can consider the below costs of materials per m2. The choice of material depends on your house’s needs, loft space, and accessibility to the installation site. Find the price per square meter for different materials for loft insulation.
| Material | Type | Avg. Cost (per m²) incl. installation |
|---|---|---|
| Mineral Wool | Roll/Loose-fill | £13 – £17.5 |
| Sheep’s Wool | Roll | £17.5 – £22 |
| Glass Wool (Fiberglass) | Roll/Loose-fill | £10 |
| Cellulose | Loose-fill | £10 – £12 |
| Polystyrene (EPS/XEPS) | Sheet/Loose-fill | £10 |
| Polyisocyanurate (PIR/PUR) | Sheet/Liquid Foam | £21.5 |
| Foil Insulation | Sheet | £4.95 to £9.08 |
Remember that these estimated prices are for thermal insulation, if you are in the market for acoustic insulation, the prices might vary for soundproof insulation. By considering your loft space, suitable material, and form of insulation, you can get more precise estimates of installation costs of insulation in your loft.
For attic insulation, usually roll or batt insulation is commonly installed. If you need draught proofing in loft joists as well, blown-in insulation can be a better choice.
Labour Costs To Install Loft Insulation
Labour costs for the loft insulation as of Feb 2025 are £250/day. If your loft cannot be insulated through DIY methods, you should consider handing over the insulation job to professional labour. If you are also installing the loft legs, the labour and material costs will be further increased.
The labour costs may vary for your insulation project depending on your property size and location. For example, professional installers in cities like London can charge premium prices as compared to rural areas.
Another thing you need to consider is your loft space requirements and accessibility. If you can reach it easily and it does not require complex installation or loose-fill insulation materials, you can install it through DIY methods.
Additional Loft Insulation In the UK Costs
While budgeting for attic/loft insulation, you should consider the potential additional costs you might observe during the installation per the method of insulation selected. Here are some of those extra costs you need to calculate for insulating your loft space.
- Pipe lagging £6–£35 m² (the process of fitting insulation materials around water pipes), includes material + labour costs.
- Insulating the water cisterns to prevent water freezing (£150 including labour)
- Installing a loft hatch and wooden ladder (£170–£290)
- Loft boarding (£55/m² material & labour) – This is optional if you want to increase the loft space or add an extra air barrier
- You might need an extra £300 to relocate the electric wires from your loft.
Considering all the potential extra costs, you will be able to stay within budget and not end up overspending beyond your capacity.
Air Source Heat Pump Grants
Factors Affecting Loft Insulation Costs
As we mentioned above, the loft insulation cost might be considerably influenced by various factors. Below we have discussed those potential factors in detail.
- Insulating Loft for Storage or Living: If your loft space is used for storage, you just need to install the loft floor insulation (known as cold loft insulation). However, if you use it for living space, you need warm loft insulation which includes draught proofing, loft rafters, inner walls and glazing.
- Damaged Loft Space: If your attic space is damaged by dampness or has draughts, you might need to solve these issues for the longevity of the insulation material.
- DIY vs Professional Installation: You can save on installation costs if you install the loft insulation through DIY methods. It is effective if you are using your loft space for storage only. You need to make this decision sensibly as it might significantly affect insulation performance and thermal resistance.
- Accessibility to the Loft: If your loft is not easily accessible, it might need the loft insulation to be installed through the blown-in insulation method. This requires a professional company and specialized equipment, which can increase the cost of loft insulation, typically £2,200 to £2,750 for a 3-bedroom semi-detached home.
Additional factors like chimneys, ventilation, walls and ceiling insulation and pipework draught proofing also require extra budget.
Can You Get Free Loft Insulation Grants to Insulate Your Loft?
Government schemes like Energy Company Obligation, the Great British Insulation Scheme, and Home Upgrade Grants provide incentives for loft insulation. If you meet the criteria, you can get hold of these government grants to install insulation in your attic space.
These grants provide complete funding through grants for loft insulation. Besides attic insulation, these grants also fund different insulation options such as:
- Cavity wall insulation
- Solid wall insulation (internal or external)
- Flat or pitched roof insulation
- Underfloor insulation
- Solid floor insulation
- Room-in-roof insulation
Through these grants, loft insulation will cost £0 as insulation measures are fully funded.
Final Thoughts
To wrap up the discussion, to improve the conductivity of your building insulation, keep it safe from damp formation, and improve its energy-efficiency you need perfect loft insulation installed.
You should consider fire-resistant materials like fibreglass insulation or foam boards for better performance. All these decisions depend on your heat-loss and heat flow requirements.
If you are deciding on the materials and costs for your home insulation, you first need to decide on the types of insulation, materials’ r value or thermal-conductivity and requirements of UK homes. In this article, we have comprehensively discussed different insulation types, and how much it costs.
Frequently Asked Questions
For installing 270 mm of mineral wool on a typical semi detached house’s loft, the cost may range around £950. However, for professionally installed loft insulation, the cost may range from £125 and £4,125, depending on your house size and other factors (discussed above).
In the fall months from September to November, it is considered the best time to install the insulation as there is less demand in those months so are the costs.
Yes, you can save a lot on labour costs by insulating your home yourself. However, there are risks involved as low-quality insulation may result in non-reduction in energy costs and lower thermal resistance. Your house will be less energy efficient and using insulation boards also might not be a great idea.
If there is a lack of ventilation or you installed too much insulation in your loft, it may cause condensation. This can be more problematic if your house has no soft vents installed to allow air to flow from the loft from outside air.
