Best Builders in Merton, London

Builders in Merton carry out extensions, loft conversions, refurbishments, kitchens, bathrooms and general repairs. Below you will find our selection of 6 builders in Merton, with address, phone number, website and opening hours for each one, followed by practical advice on choosing the right builder, typical prices and answers to common questions.

6listed
0with phone number
3with website

6 Builders in Merton

2Building Blocks

Address
15a Dundonald Road, London, SW19 3QH
Directions

3F & G Building Contractors

Address
550 Kingston Road, Raynes Park, London, SW20 8DR
Directions

4KNK Building Services Ltd

Address
Foundation House, 10 Morden Road, London, CR4 4GL
Directions

How to choose a builder in Merton

  • Check planning permission and Building Regulations requirements before work starts.
  • Get at least three detailed, itemised quotes.
  • Look for membership of the Federation of Master Builders (FMB) or TrustMark.
  • Agree a written contract with stage payments; never pay the full amount upfront.

Checks and regulation: Most structural work needs Building Regulations approval; work on shared walls may need a Party Wall agreement.

How much does a builder cost in Merton?

Single-storey rear extensions in London typically cost £2,500–£3,500 per m²; loft conversions £50,000–£90,000. Prices vary by area, time of day and the complexity of the job or service, so always ask for a written quote or check the latest price list before you book.

Builders across Merton

Merton covers neighbourhoods such as Wimbledon, Mitcham, Morden, Colliers Wood, Raynes Park, South Wimbledon, Merton Park, Wimbledon Village (postcodes SW19, SW20, CR4, SM4). The builders listed on this page are located in or around SW19, Raynes Park, CR4. Getting around is easy thanks to the District and Northern lines, London Trams, South Western Railway and Thameslink trains. If you live close to the borough boundary, it is worth comparing options in neighbouring boroughs too.

Builders in nearby boroughs

Frequently asked questions

Do I need planning permission for an extension in Merton?

Many rear extensions fall under permitted development, but conservation areas and flats have stricter rules. Check with Merton council.

How long does an extension take?

A single-storey rear extension usually takes 10–16 weeks once work starts.

What is a Party Wall agreement?

If you build on or near a shared wall, you must give your neighbours notice under the Party Wall etc. Act 1996.

Listings are compiled from public business information and OpenStreetMap (© OpenStreetMap contributors, ODbL). Details can change, so please confirm opening hours and prices with the business before visiting. Businesses can request corrections via our contact page. Last reviewed: September 2026.