Cavity wall insulation removal cost

Removal is priced by the area of wall to be cleared, so the house type and the walls that have failed matter more than anything else. Published UK guides put extraction at about £20 to £30 per square metre before VAT.

About 80 m² of wall

£1,600 to £2,400

before VAT

A guide for budgeting, not a quote. The specialist prices your walls after a camera survey.

Ask for a priced survey

Removal prices by house type

All external walls, before VAT. Wall areas are typical net figures after windows and doors, and leave out party walls, which are not filled.

House	Wall area	Extraction only	With bead refill	With wool refill
Mid-terrace house	About 45 m², front and back walls only	£900 to £1,350	£1,700 to £2,700	£1,600 to £2,350
End-terrace house	About 75 m², front, back and one gable	£1,500 to £2,250	£2,850 to £4,500	£2,650 to £3,900
Semi-detached house	About 80 m², front, back and one side	£1,600 to £2,400	£3,050 to £4,800	£2,800 to £4,150
Detached house	About 120 m², all four walls	£2,400 to £3,600	£4,550 to £7,200	£4,200 to £6,250
Semi-detached bungalow	About 50 m², three walls, single storey	£1,000 to £1,500	£1,900 to £3,000	£1,750 to £2,600
Detached bungalow	About 70 m², all four walls, single storey	£1,400 to £2,100	£2,650 to £4,200	£2,450 to £3,650

Extras that change the total

Item	When	Guide price
Borescope survey	Often free when a firm is quoting	£50 to £300
Scaffold	Tall gables, three storeys, over a conservatory	£300 to £800
Wall repairs and repointing	Before any refill	£150 to £600
Remedial wall ties	Per m² of wall treated	£30 to £50
Wall tie survey	If the lender or survey calls for one	£250 to £450
Builder’s day rate	General making good	£240 to £300

Where these prices come from

Firms that remove cavity insulation rarely publish prices, so these ranges come from national price guides written for homeowners: a trades marketplace guide with a price table last updated May 2024 (about £21 to £22 per m², £1,680 to £2,520 for a whole house), a home-improvement price guide read in November 2026 (£1,600 to £2,200 for a semi, £2,500 to £3,000 or more for a detached house), and a builders’ cost guide from April 2026 (£1,500 to £3,000 for extraction of failed insulation). We have widened the 2024 per-metre figure to £20 to £30 so that whole-house totals sit within the 2026 ranges.

Refill prices use the April 2026 guide’s installed rates: bonded polystyrene bead £18 to £30 per m², mineral wool £15 to £22. The wall areas are our own typical figures and are the biggest uncertainty: a large semi with bay windows can have more wall than a small detached house.

These are national figures. London and the South East tend to sit at the top of each range.

Official guidance used on this page

Questions about the cost

How much does it cost to remove cavity wall insulation?

About £20 to £30 per m² of wall in published UK guides. A mid-terrace is roughly £900 to £1,350, a semi-detached house £1,600 to £2,400 and a detached house £2,400 to £3,600, before VAT.

Why does removal cost more than the original insulation?

Blowing fill in takes a few hours through small holes. Getting it out means opening the wall, loosening material that may be wet, bonded or matted, vacuuming it, checking every part of the cavity by camera and relaying bricks.

Is there VAT on cavity wall insulation removal?

HMRC zero-rates installing insulation in homes until 31 March 2027. Removal is not covered by that relief, so expect 20% VAT on extraction. A refill installed before April 2027 should be zero-rated.

Can I just do the worst wall?

Often, yes. Failure is usually worst on the wall facing the prevailing weather. A survey tells you whether the other walls are sound.

Are there grants for removing cavity wall insulation?

We know of no general national grant for removal. If the insulation is guaranteed, a valid claim may pay for remedial work; that is the place to start.

What makes a quote higher?

Bonded beads or foam, mineral wool that has matted with water, scaffold, rendered walls that have to be cut, rubble in the cavity, wall ties to replace, and difficult access.

Tell us what the walls are doing

Three short steps. Your postcode, the house and what you are seeing are enough to start. The specialist confirms the detail with a borescope survey before any price is fixed.

Costs you nothing. We hold on to what you send until you have agreed to the extraction specialist we suggest.

Step 1 of 3

Where is the house?

Postcode