Which trades do you need for a London renovation?
A London renovation usually needs a designer, a structural engineer where walls or floors change, a main builder and the specialist trades the builder brings in. Most of them cannot start until the drawings, the neighbour notices and the Building Regulations notice are done. This guide sets out the order and the statutory waits.
Prefer to talk it through?
The trades, in the order they usually appear
On an extension or a full house renovation the sequence is fairly steady. A drawings professional comes first, because every other trade prices from the plans. A structural engineer follows wherever a wall comes out, an opening widens or a floor is cut, and supplies the calculations the builder and the council both need.
Then the site begins. A main contractor or site manager takes the job, and the groundworker, bricklayer, carpenter and roofer close the building in. The electrician and the plumber or heating engineer do their first fix inside the shell, the plasterer follows them, and the second fix and decoration finish the job. Which of these you hire separately, and which the main contractor brings in, is a matter of the contract you sign.
A smaller job drops several of these. A single beam through a party wall needs the engineer and one builder, not the whole list.
The notices that hold the trades back
Three pieces of paperwork decide the start date, and a builder should not start before they are in place. The first is the party wall notice. A party structure notice is served at least two months before the proposed work begins (Party Wall etc. Act 1996, section 3(2)(a)). Our guide on whether you need a party wall agreement explains when it applies.
The second is the Building Regulations notice. Under regulation 16(1)(b) of the Building Regulations 2010, work must not start until at least two days have elapsed since the end of the day the notice of intention to start was given. The third works in the other direction: a notice of completion is given not more than five days after the work is completed (regulation 16(4), on legislation.gov.uk).
If you choose the full plans route, the council must tell you its decision on the application within five weeks of receiving it, or a longer period you agree (regulation 14A(6)). Our building control guide compares the routes.
A party structure notice is served at least two months before the proposed work begins (Party Wall etc.
Where the structural engineer sits in the line
The engineer works before the builder, not alongside. The beam sizes and the bearing details come from calculations, and the builder cannot order steel or prepare the opening without them. Building control usually asks to see them as well.
Our starting fixed fee for structural calculations for a single beam or opening is £745, from the pricing page. Larger alterations are quoted from the drawings. Our explanation of structural calculations shows what the document contains, and our structural drawings service describes how we supply it.
One set of drawings for every quote
Send every tradesperson the same drawings. Quotes built on a verbal description cannot be compared, and the gaps between them become variations once the work is under way.
A set of plans also tells the electrician where the sockets sit and the plumber where the pipes run, so the trades are not left to settle it on site. That is the main thing a drawings package contributes to the build.
Sources
Every figure on this page, where it comes from and a link to the original.
| Figure | Source | Link |
|---|---|---|
| £745 | DrawingsDirect starting fixed fee for structural calculations for a single beam or opening, from the published price list | drawingsdirect.co.uk |
| two days | Building Regulations 2010 reg 16(1)(b): work must not start until at least two days have elapsed since the end of the day the notice of intention to start was given (source wording: "at least two days have elapsed") | www.legislation.gov.uk |
| five days | Building Regulations 2010 reg 16(4): notice of completion is given not more than five days after the work is completed (source wording: "not more than five days after that work has been completed") | www.legislation.gov.uk |
| two months | Party Wall etc. Act 1996 s3(2)(a): a party structure notice is served at least two months before the proposed work begins (source wording: "at least two months before the date on which the proposed work will begin") | www.legislation.gov.uk |
| five weeks | Building Regulations 2010 reg 14A(6): the authority must notify the outcome of a full plans application within five weeks of receipt, or a longer agreed period (source wording: "within five weeks beginning with the date the application is received") | www.legislation.gov.uk |