124 City Road, London, EC1V 2NX
EC1V · 2 miles in a straight line from Charing Cross
020 3123 4567Visit websiteoffice@allconstruct.co.ukOpen profile
London · Building / Extensions / Conversions
Builders in London
Phone numbers for builders in London — extensions, loft conversions and refurbishment. London boroughs only, not Slough or Reading. Open a profile and phone the business yourself. This site does not send the job.
An extension or a loft is more than a day rate. Ask what the written package includes. This London list is the City of London and the 32 London boroughs, including Croydon, Bromley, Ealing and Harrow. Slough, Watford, Reading and Luton are not added to it. Profiles show a name, the area they cover and a phone number. Public qualifications such as Gas Safe or NICEIC appear only when they are on the profile. Read the cost notes before you treat a number as the price. A figure on a card is not a quote from this site.
85 Gleneldon Road, London, SW16 2BH
SW16 · 5 miles in a straight line from Charing Cross
07785 900931Visit websiteinfo@brownbuilding.co.ukOpen profile
765 Finchley Road, London, UK, NW11 8DN
NW11 · 5 miles in a straight line from Charing Cross
22 Park Grove, London, N11 2QD
N11 · 7 miles in a straight line from Charing Cross
Unit 308 The Bon Marché Centre, 241–251 Ferndale Road, London, SW9 8BJ
SW9 · 3 miles in a straight line from Charing Cross
245 Liverpool Road, London, N1 1LX
N1 · 2 miles in a straight line from Charing Cross
Kemp House, 160 City road, London, EC1V 2NX
EC1V · 2 miles in a straight line from Charing Cross
85 Great Portland Street, London, W1W 7LT
W1W · 1 mile in a straight line from Charing Cross
Rear of 237 Gipsy Road, London, London, SE27 9QY
SE27 · 6 miles in a straight line from Charing Cross
020 8670 5771Visit websiteinfo@martinsbuilders.comOpen profile
Flat 28, Columbia Point, London, SE16 7BE
SE16 · 3 miles in a straight line from Charing Cross
28 Hoylake Road, London, W3 7NP
W3 · 5 miles in a straight line from Charing Cross
Studio 111, 132-134 Lots Rd, London, SW10 0RJ
SW10 · 3 miles in a straight line from Charing Cross
167-169 Great Portland Street, London, W1W 5PF
W1W · 1 mile in a straight line from Charing Cross
Niddry Lodge, 51 Holland Street, London, W8 7BJ
W8 · 3 miles in a straight line from Charing Cross
L H A London Ltd, Sandeman Allen, London, W2 3JB
W2 · 3 miles in a straight line from Charing Cross
No businesses match those extra filters. Clear 24-hour or qualification to widen the list.
How to read a price for extensions, loft conversions and refurbishment
The Checkatrade house extension cost guide, table last updated June 2026, puts a finished extension at £1,800–£3,000 a square metre excluding VAT, average £2,400. A shell only is £1,200–£1,700 a square metre, average £1,450, also excluding VAT. Victorian and Edwardian terraces, mansion blocks and converted flats are common, so access, parking and how waste leaves the street often sit beside the labour. The same guide says builders in London and the South East typically charge more, and that its figures are not location-based. It does not publish a London total. On a terrace, ask about party-wall access before you treat £2,400 a square metre as the job. A figure here is not a quote from this site. Checked 14 October 2026.
What to check in London
Many extensions, loft conversions and structural openings need building control, and some need planning consent. A listing is not that consent and it is not a party-wall award. Victorian and Edwardian terraces, mansion blocks and converted flats are common, so access, parking and how waste leaves the street often sit beside the labour. Then ask whether the pound-per-square-metre figure excludes VAT, and what finish it stops at.
Questions before you phone
How do I contact builders in London?
Use the phone number on the card. Open the record if you want the email or the website, when those are printed. You make the contact.
Will Local Trades UK send a builder to my home in London?
No. Nothing on this page is passed on. You phone the business. A reply is between you and them.
What should I ask a builder in London before I phone?
Many extensions, loft conversions and structural openings need building control, and some need planning consent. A listing is not that consent and it is not a party-wall award. Victorian and Edwardian terraces, mansion blocks and converted flats are common, so access, parking and how waste leaves the street often sit beside the labour. Then ask whether the pound-per-square-metre figure excludes VAT, and what finish it stops at.
Other London and building / extensions / conversions lists
All builders
Building / Extensions / Conversions lists in every city we cover.
All trades in London
Other home-service trades covering London.
Builders in Birmingham
This list is Birmingham and Sutton Coldfield. Solihull, Wolverhampton, Dudley, Walsall and Coventry are not added to a Birmingham card.
Builders in Bristol
Bristol here includes the built-up edge: Filton, Patchway, Bradley Stoke, Kingswood, Keynsham and Long Ashton. Bath, Weston-super-Mare and Yate are not on this list.
Builders in Leeds
Leeds here includes Morley, Pudsey, Horsforth, Otley, Yeadon, Guiseley and Wetherby. Bradford, Wakefield, Huddersfield and Harrogate are not on this list.
Builders in Manchester
Manchester on this site includes Salford, Trafford, Stockport, Oldham, Bolton, Bury, Rochdale, Wigan and Tameside. Warrington, Preston and Macclesfield are not on this list.
Carpenters and joiners in London
Doors, stairs and fitted joinery. A showroom that does not fit the work is not this list.
Damp proofing in London
Rising damp, penetrating damp and timber treatment. A survey on its own is not this list.
Electricians in London
Rewires, consumer units and EICRs. NICEIC or NAPIT appears only when it is on the record.
How to ask for a quote · Cost notes · Grants · Blog · All listings