Can insulation be free?

Yes — for eligible lower-income households via ECO4/Warm Homes; others get 0% VAT to March 2027.

Is solid wall insulation worth it?

It's costly but can transform an F/G home; a retrofit assessment confirms it's suitable first.

Insulation Cost (UK)

Insulation is usually the cheapest carbon and bill saving you can make. This guide gives typical UK 2026 prices per measure — and how grants or 0% VAT can cut them to zero.

Last reviewed: August 2026Sources: Energy Saving Trust · Warm Homes Plan (GOV.UK) · National Insulation Association

Typical costs by measure

Loft £300–£1,500; cavity wall £1,000–£3,500; external solid wall £8,000–£22,000; internal solid wall £4,500–£13,000; underfloor £1,000–£5,000; room-in-roof £1,500–£4,000.

Cut the cost to zero

0% VAT on insulation materials runs to March 2027. Lower-income households can get it free via ECO4 or the Warm Homes Local Grant — never pay an application fee.

What affects price

Property size, wall type, access, and whether scaffolding is needed. A whole-house plan (via PAS 2035) avoids doing measures in the wrong order.

FAQs

Can insulation be free?: Yes — for eligible lower-income households via ECO4/Warm Homes; others get 0% VAT to March 2027.
Is solid wall insulation worth it?: It's costly but can transform an F/G home; a retrofit assessment confirms it's suitable first.