For pros

Builder cost in London (2026)

Prices reviewed November 2026

The typical price in London is £2,800 to £4,000 per m² (single-storey rear extension). Building costs vary more than almost any other home job, because every project is different. These are typical London ranges to help you judge a quote.

💷 Typical builder prices in London

Single-storey rear extension£2,800 to £4,000 per m²
Dormer loft conversion£55,000 to £85,000
Kitchen refit (labour and fitting)£8,000 to £25,000
General builder day rate£250 to £350
Typical London prices in 2026. A guide only; your quotes will depend on the job.

What changes the price

  • The scope: a bigger or more complex project means more labour and materials.
  • Access and the site: a tight London street, no parking or a top floor adds time.
  • The finish: standard fittings cost far less than bespoke ones.
  • Planning and building control: fees and drawings for jobs that need them.
  • Timing: busy seasons can push prices up and start dates back.

How long it takes

Small repairs take days, a kitchen or bathroom a few weeks, and an extension or loft conversion several weeks to a few months.

How to pay less

  • Get three written quotes that break down labour and materials so you can compare like with like.
  • Settle the design before work starts: changes mid-project are expensive.
  • Keep a contingency of around 10 percent for surprises behind walls.

Before you hire

  • Ask for a written quote that breaks down labour, materials and VAT.
  • Ask for public liability insurance and a recent reference you can speak to.
  • Ask who applies for planning permission or building control approval, if the job needs it.
  • Agree a payment schedule tied to stages of work, not a large deposit up front.
  • Get the start date and expected finish date in writing.

💬 Questions about builder costs

Do I need planning permission in London?

Many rear extensions and loft conversions fall under permitted development, so they don't need full planning permission. Rules are stricter in conservation areas and for flats. Check with the council or ask builders when they quote.

How many quotes should I get?

Three is a good number for building work. It gives you a sense of the fair price and lets you compare how each builder plans the job, not just the total.

What should a builder's quote include?

A written breakdown of labour and materials, a start date and timeline, a payment schedule tied to stages of work, and who is responsible for skips, waste and making good.

Why do builder quotes differ so much?

Quotes can differ because builders price different specifications, allow different amounts for materials, or include different extras. Ask each builder to price the same written list.

Get builder quotes

These ranges are typical London prices, reviewed by us, and they are a guide rather than a quote. Your price depends on the job, the size of your home and how soon you need it. Tell us what you need and up to 3 local pros will send you a quote, so you can compare real prices instead of averages.

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