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Every home is a castle.
Build yours here · See what it costs
Your answers are drawn here
Free instant estimate
Build it here. See what it costs.
Answer one question at a time and watch your home take shape. Choose one project or several. Your indicative London price arrives at the end, on screen and by email. Free, and about two minutes.
01Your home
What kind of home is it?
designers, builders & project managers
projects completed
public & employers' liability cover
How the free estimate works
Four steps, one clear range.
- 01
Your home
Terraced, semi-detached, detached or a flat, and when it was built. The model draws it in its period, from a Victorian bay to a 1930s gable.
- 02
The work
One project or several: an extension (rear, side return or L-shaped, on one storey or two), a loft conversion, a full refurbishment, a kitchen or bathrooms. Each adds its own questions.
- 03
The brief
The finish, whether you have drawings, where planning stands, a conservation area or listing, and when you would like to start.
- 04
Your estimate
An indicative London range, line by line, on screen and by email, with a PDF to download. Free, and about two minutes.
We design and build across South West London, West London and South East London, from our office in Chiswick, W4. The estimate is indicative and free, and it is where the conversation starts: every MVV project is priced individually after a visit.
What London projects cost
The figures behind your estimate
| The work | Typical cost, ex VAT | Read more |
|---|---|---|
| New extension space, standard finish | £3,100 to £3,400 per m² of new floor | Extension costs |
| A complete extension project, once finishes and fittings are included | From around £100,000 | Extension costs |
| A two storey side return, about 48 m² of new floor | Around £151,000 | Two storey extensions |
| A rear dormer loft conversion, new stair included | £80,000 to £95,000 | Loft conversion costs |
| A whole house refurbishment with a new extension | £1,300 to £1,600 per m² of all the floor worked on | Refurbishment costs |
| The builder's work to refit a kitchen diner | Around £27,000 | Refurbishment costs |
| A family bathroom, renewed in the same layout | £16,000 to £16,500 | Refurbishment costs |
| Converting a bathroom into a wet room | Around £15,500 | Refurbishment costs |
| A new cloakroom WC under the stairs | Around £6,000 | Refurbishment costs |
From typical London jobs priced on our estimator in September 2026, calibrated to inner west London: Fulham, Chelsea and Wandsworth. Prime central London projects often price 8 to 25 percent above these figures, and outer London commonly 10 to 20 percent below. All figures exclude VAT and are indicative, not a quotation.
The detailed version · £9.99 per estimate
Every trade, priced line by line.
The free estimate gives you the range. The AI Estimator reads your own description, photos and plans, then prices the work trade by trade, from the structure to the last coat of paint, on screen and by email.
Not sure which you need? Free estimate, AI estimate or a quotation, compared
Good to know
Frequently asked questions
- How accurate is the instant estimate?
- It gives an indicative range based on your project type, size and specification. It is not a quotation. Every project is priced individually after a site visit.
- How much does a house extension cost in London?
- Our minimum for a complete house extension is around £100,000, because even a small extension carries almost the same baseline of work as a larger one. The instant estimate gives a range for your specific size and specification. Figures exclude VAT, professional fees and planning.
- Do your prices include VAT?
- Indicative figures are shown excluding VAT. VAT is charged at the standard UK rate of 20%.
- What happens after I submit an enquiry?
- We review your details and arrange a free consultation to visit the property, talk through your brief, and prepare a fully costed proposal.
Estimates are indicative ranges, exclusive of VAT, professional fees, planning and statutory costs. Every MVV project is priced individually after a site visit. The estimate is where the conversation starts, not where it ends.