How much does it cost to insulate my home and is it worth it?
Read our guide to find out how insulating your home could save you money
Key takeaways
Loft insulation starts from £300 and cavity wall insulation from £400 in the UK, with floor and solid walls costing significantly more, depending on factors like the size and age of your property
Fibreglass and mineral wool rolls are a budget-friendly option for lofts and stud walls
Great British Insulation Scheme (GBIS) and Energy Company Obligations (ECO) scheme offer free or subsidised insulation for those on certain benefits
Where does your home need insulation?
There are certain areas of your home that need insulation, including:
They account for a third of heat loss, but with cavity wall insulation, you can significantly reduce this. Cavity walls are exterior walls with two layers and a narrow gap in between. They lose less heat than solid walls, but can still be improved with insulation.
A quarter of heat escapes here, but loft insulation can keep that heat where it belongs.
They might be underfoot, but don't overlook them; 10% of heat loss can occur here.
Windows, doors, and chimneys can be sources of heat loss if not properly draught-proofed.
Walls
Roofs or lofts
Floors
Draughts
Types of home insulation
There are different types of insulation materials available, depending on which area of your home you're insulating. The most common materials include:
A popular choice due to its affordability, often used in batts or rolls, relatively easy to install.
Similar to fibreglass but made from rock or slag, offering good insulation and fire resistance.
Made from recycled paper, a more eco-friendly option, often used for loose fill in walls and lofts.
These come in various forms like polystyrene, polyurethane, or PIR, offering high R-value and good moisture resistance, suitable for walls, floors, and roofs.
Applied by professionals, spray foam creates a continuous insulation layer, effectively sealing gaps and air leaks.
Materials like fibreglass, mineral wool, or cellulose can be blown into wall cavities and lofts, providing insulation where access is limited.
Fibreglass
Mineral wool
Cellulose
Rigid foam boards
Spray foam
Loose fill
How much does home insulation cost?
The cost of house insulation varies widely depending on the type of insulation, the size and type of your home, and whether you are insulating walls, lofts, or floors.
Generally, you'd expect to pay anywhere from £300 for loft insulation to over £14,000 for external wall insulation on a larger property.
Type of insulation | Average installation cost | Estimated annual energy savings | Benefits |
|---|---|---|---|
£300 – £500 | £150 – £250 | One of the quickest returns on investment | |
£400 – £800 | £120 – £270 | Great for homes built after 1920s | |
£4,000 – £7,000 | £250 – £450 | Higher cost but significant energy savings | |
Solid wall insulation (external) | £8,000 – £12,000 | £260 – £480 | Improves appearance too |
Floor insulation | £1,200 – £2,000 | £60 – £120 | Best for ground floors and basements |
Draught proofing | £100 – £200 | £20 – £50 | Simple, low-cost energy saver |
What home insulation grants are currently available in the uk?
As of April 2025, UK residents have access to several government-backed energy schemes offering free or subsidised home insulation to improve energy efficiency and reduce heating bills.
The main schemes currently available are:
Launched in April 2023 and running until March 2026, GBIS (formerly ECO+) is a £1 billion initiative aimed at helping households insulate their homes.
It targets properties with low energy efficiency (EPC ratings D–G) and Council Tax bands A–D in England (A–E in Scotland and Wales). The scheme offers free or heavily discounted insulation measures, including:
Loft insulation
Cavity wall insulation
Solid wall insulation (internal or external)
Underfloor and solid floor insulation
Room-in-roof insulation
Eligibility is divided into two groups:
General Group: Households meeting the EPC and Council Tax criteria may receive a single insulation measure, with a possible contribution required.Wikipedia
Low-Income Group: Households receiving certain means-tested benefits may receive a single insulation measure, potentially including heating controls, with no contribution required.Wikipedia
To check eligibility and apply, visit the official GBIS page on GOV.UK.
Running until March 2026, ECO4 is a long-standing scheme obligating large energy suppliers to fund energy-saving measures for low-income and vulnerable households.
It focuses on improving the least energy-efficient homes (EPC ratings D–G) through a whole-house approach, which may include:
Insulation (loft, cavity wall, solid wall)
Heating upgrades
Solar panels
Eligibility typically requires households to receive certain income-based benefits, such as:
Universal Credit
Pension Credit
Income Support
Child Tax Credit
Working Tax Credit
Local authorities can also refer households under the ECO4 Flex scheme. For more information, visit the Ofgem ECO4 page.
Offers up to £15,000 for energy efficiency upgrades in low-income households.
Great British Insulation Scheme (GBIS)
Energy Company Obligation (ECO4)
Warm Homes Grant
What are the benefits of insulating your home?
There are many advantages of insulating your home, such as:
Reduced energy bills
Smaller carbon footprint
Warmer and cooler home throughout the changing of the seasons
Noise reduction
Improved air quality
Moisture control
Increased property value
Is home insulation worth it in the UK?
Yes, although the initial investment cost is quite high, home insulation in the UK is generally worth it long term. It offers significant cost savings and other benefits. Insulating your home can reduce heat loss, lower energy bills, and improve comfort and health.
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Which insulation is best for old houses?
For insulating old houses, mineral wool (like rockwool or glasswool) is often the best choice, especially for cavity walls, as it's breathable and fire-resistant.
Other good options include sheep's wool or hemp, which are natural, renewable, and breathable. Cellulose insulation, made from recycled paper, is also a good, environmentally friendly option, especially for blown-in applications.
What is the cheapest way to insulate a house?
The cheapest way to insulate your home on a budget is to focus on areas with significant heat loss, like windows and doors, and use cost-effective materials like draught-proofing and thermal curtains.
If you need to upgrade your loft insulation or install floor insulation with underlay, check if you're eligible for free insulation grants.
How long does home insulation last?
Home insulation can last between 15 to 100 years, depending on the material and installation quality. Fibreglass and cellulose insulation typically last 20-30 years, while mineral wool and spray foam can last up to 100 years. Cavity wall insulation is designed to last the lifetime of the building, often 20-100 years.
Is cavity wall insulation still recommended?
Yes, insulating cavity walls is generally recommended. By filling the gap between the two walls of a cavity wall, you can significantly reduce heat loss, saving money on heating bills and reducing your carbon footprint.
However, it's crucial to ensure proper installation and address any existing damp issues before proceeding, as incorrect installation can lead to damp problems.
