London Renovation Cost Calculator: Estimate Your Refurbishment Budget per m²

The design fee is rarely the main expense. A full London renovation runs roughly £800 to £3,500 per square metre depending on specification, and the build dwarfs everything else. Enter your floor area and finish level to get a realistic budget, split into build, design fee and contingency.

Per square metre rates cover the building work and finishes. Furniture and appliances sit on top and vary hugely with taste. Read the full breakdown in our guide to what an interior designer costs in London.

Renovation cost per m² in London: the rates this calculator uses

The calculator works from four specification bands for Greater London, then adjusts for location: about 15% more in zones 1 and 2, where access, parking suspensions and labour rates push prices up, and about 22% less outside London. If you add a new kitchen or bathroom, the whole rate goes up by 12%, because those rooms pack plumbing, tiling, electrics and joinery into a few square metres.

On top of the build the calculator adds a 12% contingency, and, if you tick it, an interior designer's fee of 7% to 12% of the build.

Refurbishment cost examples: what typical London projects come to

These are the calculator's own results for four common jobs, so you can sense-check a quote before you run your own numbers.

Measure the floor area you are actually renovating, not the whole property. A kitchen and bathroom refit in a 110 m² house is a 20 m² job priced at the kitchen and bathroom rate, not a 110 m² one.

What a renovation cost calculator cannot see

• VAT. Builders charge VAT at 20% on most renovation work, so check whether each quote includes it. If the home has not been lived in for the two years before work starts, the work can qualify for the 5% reduced rate, under section 8 of HMRC's VAT Notice 708. Proof such as council tax or electoral roll records may be asked for.
• Party wall costs. Most London terraces and semis share walls. Work covered by the Party Wall Act needs notice to the neighbour between two months and a year before you start, and they have 14 days to reply in writing, according to GOV.UK. If they dissent, surveyors' fees are added to your bill.
• Structural and professional fees. Knocking through walls means a structural engineer's calculations and Building Regulations sign-off, and possibly planning permission or listed building consent. None of those are in the per m² rate.
• Furniture, appliances and window treatments. These vary too much with taste to model, so the calculator leaves them out.
• Living elsewhere. A full refurbishment usually means moving out. Rent or storage for the length of the job is a real cost that rarely makes it into the budget.

Frequently asked questions

How much does it cost to renovate per square metre in London?

The calculator uses £800 to £1,200 per m² for a light refresh in Greater London, £1,200 to £1,800 for a mid-range refurbishment, £1,800 to £2,500 for high end and £2,500 to £3,500 for luxury or heritage work. Central London runs about 15% higher.

How much does it cost to refurbish a 60 m² flat in London?

For a mid-range refurbishment in Greater London the calculator gives £72,000 to £108,000 for the build, or £80,640 to £120,960 once a 12% contingency is added. A light refresh of the same flat comes to roughly £54,000 to £81,000 with contingency.

How much contingency should I add to a London renovation?

Between 10% and 15% of the build. The calculator uses 12%. Older London houses throw up surprises once walls and floors are opened, such as rotten joists, old wiring or party wall issues, and the contingency is what pays for them.

Do renovation quotes include VAT?

Not always, so ask. VAT-registered builders charge 20% on most renovation work. Work on a home that has been empty for at least two years can be charged at the reduced 5% rate.