Costs
What our London projects actually cost
, 6 min read
Most cost guides quote a national average that means very little in London. So here are the real budget ranges and timescales from five of our recent projects, what each one included, and what tends to push a price up or down.
Five recent projects, side by side
| Project | Area | What was done | Time on site | Budget range |
|---|---|---|---|---|
| Whole house: refurbishment, extension, loft and garden | Wimbledon | Full internal refurbishment, brick-built rear and side extension, dormer loft conversion with new oak staircase, landscaped garden | 20 weeks | £180,000 – £240,000 |
| Two-storey extension | West Hampstead, NW6 | Two-storey rear extension in a conservation area, full-height timber-framed glazing, handmade kitchen, internal refurbishment | 6 months | £180,000 – £220,000 |
| Extension and full refurbishment | Fulham, SW6 | Side and rear extension, full house refurbishment, luxury bathroom, new kitchen, underfloor heating | 10 weeks | £95,000 – £120,000 |
| Full house refurbishment | Forest Hill, SE23 | Full strip-out and refurbishment, new kitchen and bathrooms, new heating, plumbing and electrics, joinery | 12 weeks | £85,000 – £110,000 |
| Side and rear extension | Latimer Road, E7 | Side and rear extension with steels across the house, cedar cladding, oak-framed glazing, new kitchen and dining space | 10 weeks | £65,000 – £85,000 |
These are the budget ranges for those specific houses. Your home, the specification you choose and how easy the site is to work on will all change the number, which is why every one of our quotes starts with a site visit.
What pushes the price up
Structural work. Taking out walls, putting in steels or opening up the back of the house adds engineering, temporary support and time. Both of our side return projects needed steels across the full width of the house.
Glazing. Large sliding doors, full-height glazing and timber-framed screens are one of the biggest single line items in a modern extension.
Conservation areas and listed buildings. Matching materials, extra drawings and working with conservation officers all add cost. Our West Hampstead extension was designed and agreed with conservation officers before work began.
Specification. Kitchens, bathrooms, flooring and joinery can vary several times over in price for the same room.
Doing more at once. A bigger scope costs more in total, but combining an extension, loft and refurbishment means one set of scaffolding, one party wall process and one period of disruption, which usually works out better value than doing them years apart.
Other costs to budget for
On top of the build itself, allow for architect and structural engineer fees, planning or lawful development certificate fees, building control fees, party wall surveyor fees if your neighbours appoint one, and the cost of living elsewhere if you need to move out. We also recommend keeping a contingency of 15 to 20 percent for things nobody can see until walls and floors are opened up.
What our quotes include
After a site visit we send a detailed written quote with a clear scope of works, material specifications and a timeline, so you can see exactly what you are paying for and compare it fairly with other builders. You can see more about each job on our projects page.
Questions about cost
Why do building projects cost more in London?
Labour and materials cost more, sites are tighter, parking and skip permits add up, and many streets are in conservation areas or involve shared walls, which brings extra paperwork and care. All of that is reflected in London prices.
How accurate are these budget ranges?
They are the actual ranges for the projects listed. They are a useful guide to scale, not a quote for your home. We price every job from a site visit with an itemised quote.
Can I spread the work over time to manage the budget?
Yes. Phasing is common, for example doing the extension first and the loft later. It can cost more overall because some set-up costs are paid twice, so we are happy to price both options.
See the projects
Full refurbishment + rear extension, landscaping and loft conversion
Comprehensive property transformation featuring full house refurbishment, rear extension, complete garden landscaping, and loft conversion creating a stunning multi-level family home.
Side and rear extension
Modern side and rear extension creating additional living space with contemporary design, premium finishes, and seamless integration with the existing property.
Want a price for your project?
Fill in what you can and your message writes itself. Send it on WhatsApp or by email, whichever is easier.
- Rather talk? 0844 818 0188
- Want us to come and look? Book a site visit
- Need a detailed price? Get a full quote
Members of the Federation of Master Builders. What this means