How much does loft insulation cost in 2026?
Loft insulation is one of the cheapest home upgrades you can make — and one of the most worthwhile. Here's a straight answer on what it costs, what changes the price, and what you get back.
If you've started looking into loft insulation, you've probably found that getting a straight price online is harder than it should be. So let's be direct: professional loft insulation typically starts from around £1,400, fully fitted. What moves the number up or down comes down to a handful of practical things.
What affects the cost of loft insulation
- The size of your loft. Bigger roof area means more material and more time.
- What's already up there. An empty loft is a clean job; old or damp insulation may need clearing first.
- Access. A standard hatch is easy; awkward access or stored belongings take longer.
- Whether you board over it. Raised boarding for storage is an optional extra.
Why "270mm" keeps coming up
The current recommended depth for mineral wool loft insulation is around 270mm. Many older homes were insulated to 100mm or less — topping up to full depth is usually the difference-maker.
How much will it save me?
Because roughly a quarter of a home's heat escapes through an uninsulated roof, the savings are real and ongoing. The Energy Saving Trust estimates that insulating an uninsulated loft to 270mm saves a gas-heated semi-detached home around £580 a year, and a detached home around £355 a year (2026 prices). If you're only topping up from 100mm to 270mm, the saving is smaller — around £135 a year — because the first layers do most of the work. Actual savings vary with your property, heating and tariff.
Want a fixed price for your loft? Book a free survey and we'll give you an exact quote.
How to get an accurate price
Online "average" prices only get you so far, because lofts vary so much. The only way to know your real cost is a quick survey that measures your loft area, checks existing insulation and access, and accounts for any boarding you want. That's why we give a fixed written quote after a free survey rather than a vague figure over the phone.