What cavity wall insulation removal costs in 2026
Roughly £22 per square metre of wall to get it out, according to the published averages. Usually £1,600–2,200 for a semi before refilling. Work out your own range below.
Your house, roughly
Blowing it in took an afternoon. Getting it out means drilling or lifting bricks every metre or so and vacuuming the cavity floor to ceiling. So it’s priced by the square metre of wall.
Pick the nearest house type, or type in your wall area if you know it. It’s a guide from published rates, not a quote.
Extraction £1,400–2,300, refill £1,100–2,300.
Rates used: extraction £18–26/m² dry, £22–30/m² wet, around the £21.50–22 UK averages. Refill £15–30/m². Making good £200–1,000. Check whether quotes include VAT.
Cavity wall insulation removal cost, by source
Cost guides don’t agree to the pound, and none of them has seen your wall. Here’s what each one says, so you can see the spread rather than one tidy number.
| Source | What it says | Dated |
|---|---|---|
| Checkatrade, quoted by Travis Perkins | UK average removal cost £21.50 per m² | May 2024 |
| The Eco Experts | About £22 per m², around £2,100 for a whole property | Undated |
| MyBuilder | Semi-detached £1,600–2,200; detached £2,500–3,000 or more | Undated |
| Bookabuilder | Installing new cavity insulation £15–30 per m² (the refill) | 2026 |
Sources: Travis Perkins, The Eco Experts, MyBuilder, Bookabuilder. Read October 2026.
What the quote usually leaves out
This is where two quotes that looked the same end up a thousand pounds apart.
| Refilling the cavityOtherwise you’ve paid to make the house colder. | Otherwise you’ve paid good money to make the house colder. Ask what they’d refill with and why it suits your wall. | £15–30 /m² |
|---|---|---|
| Making good insideStained plaster, mouldy paint. | Stained plaster and mouldy paint. Give the wall time to dry first. Rough guide only. | £200–1,000 |
| Fixing the actual causePointing, gutters, render. | Pointing, gutters, cracked render. Skip it and the new insulation gets wet in exactly the same way. How to spot them » | varies |
| Making good outsideFilling the holes, matching the mortar. | Filling the extraction holes and matching the mortar colour, so your house doesn’t look like a dartboard. | ask |
| VATAsk if the price includes it. | Some firms quote “plus VAT”. Ask, and get the answer in writing. | +20% |
Real quotes, side by side
The figures above come from published cost guides. I’m asking working extraction firms to price the same three houses: a mid terrace, a 1960s semi and a detached. Their answers go here with VAT included, so you can see real prices next to each other.
Extraction costs: common questions
Could it cost me nothing?
Possibly. If your insulation was fitted by a registered installer from 1995 onwards and it’s the cause of the problem, a CIGA guarantee may cover the repair for free. Check before you pay anyone, and don’t let anyone disturb the insulation first. How to check »
Why do quotes for the same house vary so much?
Mostly because they include different things. One covers extraction only. Another includes refilling, making good the holes and VAT. Wet, compacted insulation also takes longer to get out than dry loose fill, and that’s more common in exposed, wet areas. Ask for an itemised quote and compare line by line.
How long does extraction take?
Often a day or two for a typical house, longer for wet insulation, big walls or difficult access. The firm will tell you after they’ve looked inside the cavity.
Is it messy?
Mostly outside. The work is done from the outside of the wall, with the waste vacuumed into bags or a lorry. Ask how they’ll protect paths, plants and the neighbour’s car.
Can I just leave it?
If your walls are dry and nothing’s wrong, yes, and you should. Extraction only makes sense when the insulation is actually causing a problem. The 60-second check »
Is there a grant for extraction?
I haven’t found a government grant for taking cavity insulation out. If someone cold calls offering “free removal”, there’s usually a compensation claim attached, with them taking a cut. Read this first »