Knock down and rebuild: Costs & Planning

What is a knock down and rebuild?

Knock down and rebuild means demolishing an existing house and building a new one in its place, often a bungalow or poorly built post-war house replaced by a larger, more efficient home. Because the new house counts as a new dwelling, the build is usually zero-rated for VAT.

New house under construction with scaffolding and roof trusses on a cleared plot

We assess whether rebuilding is better value than extending and renovating, prepare the planning application for the replacement dwelling, manage the demolition notice and asbestos survey, then build the new home. The process runs much like a new build once the old house is cleared.

Typical time on site: 36 to 60 weeks
Guide price: £2,100 to £3,700 per m², plus demolition
Building regulations: Required

What is included?

Feasibility: rebuild versus extend and renovate
Planning application for the replacement dwelling
Asbestos survey, demolition notice and service disconnections
Demolition and site clearance
New foundations, structure and full fit-out
Reconnection of services and landscaping

How much does a knock down and rebuild cost?

Replacing a bungalow with a 160 m² two-storey house at a good specification typically costs around £430,000 to £530,000 including demolition.

Knock down and rebuild	Guide price
Demolition and site clearance (total)	£15,000 to £35,000
Rebuild, standard specification (per m²)	£2,100 to £2,600 per m²
Rebuild, good specification (per m²)	£2,600 to £3,100 per m²
Rebuild, high specification (per m²)	£3,100 to £3,700 per m²

Unit: per m² rebuild (VAT zero-rated where it qualifies), plus demolition. Guide ranges only; your price is fixed in writing after the survey.

Use the guide price tool for a figure based on your size and specification, or see all guide prices.

Does a knock down and rebuild need planning permission?

England

This needs full planning permission from the council. We prepare the drawings and supporting documents, submit the application and respond to the planning officer. Decisions on minor applications usually take around eight weeks once validated.

Wales

This needs full planning permission from your council in Wales. We prepare and submit the application and deal with the planning officer on your behalf.

Scotland

This needs planning permission and a building warrant from your council in Scotland before work starts. We prepare both applications.

Northern Ireland

This needs full planning permission from the council in Northern Ireland, plus building control approval.

What about building regulations?

Full building regulations approval for the new dwelling. Demolition requires notice to the council in many cases, and an asbestos survey before any demolition.

What should I think about before starting?

A replacement dwelling is usually zero-rated for VAT where the old house is demolished completely to ground level.
You will need somewhere to live for most of a year.
Planning policy on replacement dwellings varies, especially in green belt and countryside.
Asbestos is common in post-war houses and must be removed by licensed contractors where required.

How does the project run?

Tell us about the project. Call, use the guide price tool or send the form with a few photos and a postcode.
Site visit. We walk the plot or existing house, look at access, levels, services and boundaries, and talk through what could be built.
Design and fixed price. You get drawings and a written price for the agreed specification before anything is ordered.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Questions about knock down and rebuild

Is it cheaper to knock down and rebuild or renovate?

It depends on the existing house. Where a house needs major structural work and a large extension, rebuilding can be similar cost and gives a better result. We compare both at feasibility.

Is VAT charged on a knock down and rebuild?

Usually not on the new house, if the old one is demolished completely and the new building is a qualifying dwelling.

Do I need planning permission?

Yes, for the replacement dwelling.

How long does it take?

Around 36 to 60 weeks including demolition.

What happens about asbestos?

An asbestos survey is done before demolition and any asbestos is removed safely first.

Related projects

Guides

Where do we build knock down and rebuild?

We take on knock down and rebuild across England, Wales, mainland Scotland and Northern Ireland. Choose your area: