Site survey and measured drawings
The inspection identifies access constraints, hidden defects and the information a tradesperson needs to price the work without avoidable provisional allowances.
Builder service guide
House extension builders
Plan a brighter, better-connected extension with a team that can explain structure, approvals, drainage and finishes before work begins.
Free for homeownersUp to three quotesLocal trade matchingNo obligation to hire
Typical project budget
£35,000–£95,000
Use this as a planning range only. Your property, region, specification and access determine the final quotation.
What the work can include
Foundations, walls and roof structure
Ask for this stage to be described in the written scope, including the materials, workmanship standard, access arrangements and what a finished result looks like.
Windows, doors and weatherproofing
Ask for this stage to be described in the written scope, including the materials, workmanship standard, access arrangements and what a finished result looks like.
First and second fix plus decoration
Ask for this stage to be described in the written scope, including the materials, workmanship standard, access arrangements and what a finished result looks like.
How to compare quotations
Floor area and storey count
Ask the tradesperson to define this allowance, its exclusions and the evidence they will provide at handover so every quote can be compared fairly.
Ground conditions and access
Confirm who pays for access equipment, parking restrictions, protection and any return visit caused by difficult or limited access.
Kitchen or bathroom services
Ask the tradesperson to define this allowance, its exclusions and the evidence they will provide at handover so every quote can be compared fairly.
Architect, Building Regulations and warranty fees
The quote should name the required registration, certificate or warranty and state who will arrange it after the work is complete.
Questions homeowners ask
Do I need planning permission?
Some extensions fall under permitted development, but the limits and a lawful-development route should be checked for your property.
Can one builder manage the whole project?
A principal builder can coordinate trades, but ask exactly what is included and who handles design, certification and warranty work.
What should an extension quote show?
Look for drawings, specification, exclusions, provisional sums, payment stages and a process for approving variations.