House renovation cost calculator
Renovation is priced per square metre by the trade, so that is how this works. Set the floor area, how far you are going and the age of the building.
Last updated July 2026 · built by working UK builders
If the property has been empty for two years or more, most of the work qualifies for the reduced 5% VAT rate rather than 20%. Very few homeowners claim it. Ask your builder before they price the job.
A 15% contingency on a renovation is not pessimism — on pre-war housing stock it is arithmetic.
The rates behind this calculator
All figures are 2026 UK prices for a competent, insured, VAT-registered contractor. Costs are shown as ranges because building work is delivered in ranges. A “×” value multiplies the whole build cost.
How far are you going?
| Option | Cost | Effect on total |
|---|---|---|
| Cosmetic refresh Decorate, floors, new kitchen and bathroom, nothing structural — £450–£750/m² | £450–£750 per m² | Added |
| Full refurbishment Rewire, re-plumb, re-plaster, new kitchen and bathrooms — £1,000–£1,700/m² | £1,000–£1,700 per m² | Added |
| Back to brick Strip to the shell, new floors, structural work, everything new — £1,700–£2,700/m² | £1,700–£2,700 per m² | Added |
| Derelict / uninhabitable Roof, structure, damp, the lot — £2,300–£3,600/m² | £2,300–£3,600 per m² | Added |
Age of the property
Older buildings need breathable materials, more making good, and more surprises behind the plaster.
| Option | Cost | Effect on total |
|---|---|---|
| Pre-1919 (solid wall, lime plaster) | — | ×1.15 |
| 1919–1945 | — | ×1.05 |
| 1945–1980 | — | ×1 |
| 1980 onwards | — | ×0.93 |
| Listed or in a conservation area | — | ×1.35 |
Major items on top
These sit outside the per-m² rate because they either apply or they do not.
| Option | Cost | Effect on total |
|---|---|---|
| New roof covering | £8,000–£22,000 | Added |
| New boiler and full central heating system | £5,500–£12,000 | Added |
| All new windows and external doors | £7,000–£25,000 | Added |
| Damp-proofing and replastering to affected walls | £2,500–£9,000 | Added |
| Structural work — beams, underpinning, wall removal | £6,000–£30,000 | Added |
| Single-storey extension included | £40,000–£80,000 | Added |
| Loft conversion included | £45,000–£75,000 | Added |
| Insulation upgrade — walls, loft, floors | £4,000–£18,000 | Added |
| Drainage renewal | £2,500–£9,000 | Added |
| Landscaping and driveway | £4,000–£20,000 | Added |
| Asbestos survey and removal | £800–£6,000 | Added |
Will you be living there during the work?
| Option | Cost | Effect on total |
|---|---|---|
| No — empty property | — | ×1 |
| Yes, living in it Slower, phased, more protection | — | ×1.18 |
Where is the property?
Labour rates and builder demand vary more than materials do.
| Option | Cost | Effect on total |
|---|---|---|
| London | — | ×1.25 |
| South East | — | ×1.12 |
| South West | — | ×1.03 |
| East of England | — | ×1.03 |
| Midlands | — | ×0.97 |
| North of England | — | ×0.92 |
| Wales | — | ×0.92 |
| Scotland | — | ×0.95 |
| Northern Ireland | — | ×0.85 |
Applied to every total
| Item | Amount |
|---|---|
| Design, engineer & building control | 5–10% of build cost |
| Contingency | 15% of build cost |
| VAT | Included at 20% unless stated |
The four levels, honestly described
Cosmetic refresh — £450 to £750 per m²
Nothing structural, nothing behind the plaster. New kitchen and bathroom, floors, doors, decoration, maybe new radiators. The house looks transformed and is fundamentally unchanged. Fine if the wiring, heating and roof are sound — and a mistake if they are not, because you will be pulling that new plaster off in three years.
Full refurbishment — £1,000 to £1,700 per m²
Rewire, re-plumb, new heating, re-plaster throughout, new kitchen and bathrooms, new joinery and decoration. The building fabric stays; everything in it is renewed. This is the sensible default for a 1930s–1970s house that has not been touched since the eighties.
Back to brick — £1,700 to £2,700 per m²
Strip to the shell. New floors, structural alterations, insulation, sometimes new windows and roof. You are effectively building a new house inside an old envelope, which is why the cost approaches new-build rates.
Derelict — £2,300 to £3,600 per m²
Roof off or failing, no services, structural movement, damp throughout. Every trade starts from nothing and works around a building that fights back. Budget generously and get a structural engineer involved before you buy, not after.
Sequence matters more than anything else
The most expensive mistake in renovation is doing things in the wrong order. Plaster before the roof is fixed. Floors before the heating is finished. Decoration before the building has dried. Every one of those means paying twice for the same work.
The correct order is boring and rarely followed: watertight, then structural, then strip out, then first fix, then plaster, then dry, then second fix, then decorate.Drying is a real programme item — a re-plastered pre-war house needs weeks, not days, and forcing it with heat causes cracking.
What to check before you buy a renovation project
- Roof and gutters — the source of most other problems in the building.
- Signs of movement — diagonal cracking, sticking doors, sloping floors.
- Wiring type — rubber or lead-sheathed cable means a certain full rewire.
- Damp — and whether it is rising, penetrating or condensation, because the three cost wildly different amounts.
- Asbestos — artex, floor tiles, soffits, flue pipes. Common pre-2000 and expensive to discover late.
- Drains — a CCTV survey costs a couple of hundred pounds and can save five figures.
- Planning history — unpermitted work you inherit becomes your problem.
The VAT point almost nobody uses
If the property has stood empty for two years or more, the reduced 5% VAT rate applies to most of the renovation work. On a six-figure project the saving runs to five figures. The builder must apply the rate at invoice stage, so it has to be agreed before pricing — and you need evidence of the empty period, usually a letter from the council's empty property officer.
Frequently asked questions
How much does it cost to renovate a house in the UK in 2026?
A cosmetic refresh runs £450–£750 per m². A full refurbishment with rewire, re-plumb, re-plaster, new kitchen and bathrooms is £1,000–£1,700 per m². Back-to-brick is £1,700–£2,700 per m², and a derelict property can exceed £3,500 per m². On a typical 90m² three-bed semi that means roughly £45,000 for a refresh and £110,000–£170,000 for a full refurbishment.
Can I claim the reduced 5% VAT rate?
If the property has been empty for two years or more immediately before work starts, most renovation work qualifies for 5% VAT instead of 20%. On a £120,000 renovation that is around £15,000. Your builder has to apply the rate — you cannot reclaim it yourself — so raise it before they price the job, and be ready to evidence the empty period with council tax or electoral roll records.
What order should renovation work happen in?
Make it watertight and structurally sound first — roof, gutters, damp, structural repairs. Then strip out, then first fix electrics and plumbing, then plastering and drying time, then joinery and second fix, then decoration and floors last. Doing anything decorative before the building is dry is money you will spend twice.
How much contingency do I need?
15% on any pre-war property, and 20% if it has been empty or neglected. Renovation contingency is not padding — it is the budget line for the things nobody could see until the plaster came off, and on older housing stock there is always something.
Is it cheaper to renovate or extend?
Per square metre, renovating existing space is usually cheaper than building new space. But renovating does not add floor area, and floor area is what valuers pay for. The best-value projects normally combine a modest extension with a full refurbishment of what is already there, done in one visit rather than two.