How to find a good builder in London?

The best builders in London are found on your own street, not on page one of Google. If a neighbour three doors down has had a loft or extension done on the same Victorian terrace as yours, knock and ask who did it and whether they would use them again. Period streets in Dulwich, Sydenham and Crystal Palace throw up the same problems house after house (shallow footings, lime plaster, party walls that lean), so a builder who has already worked on your exact house type is worth ten glossy websites.

Local architects and surveyors are the referral route most people miss. They see builders' work with the walls open, not just the finished paint, and they know who priced honestly and who buried costs in extras. If a structural engineer has signed off a firm's steelwork on three jobs, that tells you more than fifty online reviews. Ring a practice that works in your area and ask who they would put on a tender list.

Then ask to visit a live site. Any firm doing decent work nearby will say yes. Look at the state of it mid-build: floors protected, materials stacked under cover, one person clearly in charge. A chaotic site on a Tuesday becomes a chaotic invoice on completion day. We tell people to run every one of these checks on us too. Come and see one of our jobs in Lewisham or Beckenham half-finished; that is when you learn what a builder is actually like.