Builders: What They Do and How to Hire
General builders cover everything from extensions to renovation — here is how to choose.
4 min read · Updated 2026
Key takeaways
- ›General builders project-manage extensions and renovations end to end.
- ›Day rates £200–£400; large jobs priced as a fixed contract.
- ›A good builder will sub-contract specialists for electrics and gas.
What a builder does
A general builder manages the structure and finishing of building work — foundations, brick and blockwork, framing, plastering, roofing, and project management of sub-contractors. For a full extension they will usually bring in (or recommend) a groundworker, electrician, plumber and roofer. They often handle planning and Building Regulations submissions or work with your architect.
Typical prices (UK 2026)
- •Single-storey extension: £1,800–£3,000 per m².
- •Double-storey extension: £1,500–£2,500 per m².
- •Builder day rate: £200–£400.
- •Bricklayer day rate: £180–£280.
- •Project management fee: 10–15% of the build cost (if used).
Questions to ask and common mistakes
Ask for recent references, proof of insurance and whether they will use sub-contractors for specialist trades. Common mistakes: no written contract, paying too much up front, and not agreeing a completion date. A builder who is reluctant to put anything in writing is a risk.
- ☐Can I see two recent references and photos?
- ☐What insurance do you hold (Public Liability, Employer Liability)?
- ☐Who will do the electrics and gas — are they certified?
- ☐What are the payment stages, and when is the final payment?
Frequently asked
Should I use a builder or a main contractor?
A main contractor manages everything for a fee; a general builder is usually cheaper but you may project-manage more yourself.
Related guides
Electricians: What They Do and What to Check
When you need a qualified electrician and how to make sure they are Part P registered.
Plumbers: What They Do and When to Call One
From leaks to full bathroom fits, here is what a plumber covers and what to check.
Roofers: What They Do and What to Check
New roofs, repairs and flat roofs — plus the extras that catch quotes out.
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