Loft Insulation Cost UK 2026

Loft insulation (270 mm to current UK building regs) for a 3-bed UK semi costs £450–£700 in 2026. Top-up from existing 150 mm to 270 mm is around £300–£500.

Quick answer

Typical UK price range: £450–£900. Typical time: 1 day.

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Insulation type Loft insulation (270mm) Cavity wall insulation External wall insulation Internal wall insulation Spray foam loft (open-cell)

Area to insulate (m²)

Region London South East South West Midlands North of England Scotland Wales Northern Ireland

Specification level Basic / standard Mid-range Premium / high-end

Extras

Pre-install survey £80–£200 Vapour control layer £150–£400 Ventilation upgrade £200–£600

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Estimate only. Prices reflect 2026 UK market data — get quotes from local tradespeople for accurate pricing.

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Budget Under £5,000 £5,000 – £15,000 £15,000 – £30,000 £30,000 – £60,000 £60,000+ Not sure

Timeline As soon as possible 1 – 3 months 3 – 6 months 6+ months Just researching

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Key points

• £450–£700 for a 3-bed semi (full 270 mm install)
• Top-up (existing 150 mm): £300–£500
• £15–£30/m² installed
• Saves £225–£400/year on heating bills

Cost breakdown

Item	Low	High
Loft insulation 270 mm (full install)	£450	£700
Top-up from 150 mm	£300	£500
Boarding above (storage)	£500	£1,500

Cost by UK region

Region	Typical cost
London	£911
South East	£843
South West	£742
Midlands	£675
North England	£607
Scotland	£641
Wales	£607

How to save money

• Check ECO4 eligibility — free install if you qualify
• Never compress insulation with loft boarding — use raised loft legs
• Always upgrade ventilation when adding insulation

How to find a trusted tradesperson

Get at least 3 quotes from vetted UK trade networks:

• Checkatrade
• MyBuilder
• Bark

FAQs

Can I get free loft insulation?

Yes — through ECO4 if you receive certain benefits, or the Great British Insulation Scheme if your home has EPC D or below.

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Disclaimer: Prices are guide ranges based on 2026 UK market data. Get quotes from local tradespeople for accurate pricing.