Loft conversion cost London/Mayfair
W1 · Westminster · 2026 prices

Loft conversion cost
in Mayfair.

Mayfair — W1 — the Georgian and early Victorian district between Hyde Park and Regent Street. Most properties are commercial or converted to flats; remaining single-family homes are among the most valuable in London.

£59k–£286k
typical Mayfair range
W1
Westminster
5.5 km
from our Fulham studio
12-month
Workmanship warranty on second-fix fittings, signed by the trades
Mayfair housing stock & planning

What makes loft work in Mayfair distinct.

Housing: Georgian and early Victorian terraces, plus mews properties; many Grade II or Grade II* listed.

Planning: Mayfair Conservation Area, with overlapping Hanover Square, Conduit Street and Berkeley Square conservation areas. A high listed-building density.

Applications go to City of Westminster. We submit on your behalf and handle conservation officer correspondence end-to-end.

Streets we work in Mayfair
Mount StreetCharles StreetHill StreetBrook StreetBerkeley Square
Loft prices for Mayfair, by type

The five loft types — W1 numbers.

All figures inclusive of design, planning, build, contingency and VAT. The Mayfair multiplier (1.30×) reflects local labour, scaffolding logistics, conservation requirements and finish expectations.

Velux / rooflight only
Mayfair typical
£59k£98k
Roof stays as-is. Cheapest route, limited headroom, almost always PD.
Rear dormer
Mayfair typical
£98k£156k
The London classic. Full standing height across most of the floor.
L-shape dormer
Mayfair typical
£124k£195k
Dormer + side return at loft level. Master + en-suite typical.
Hip-to-gable + rear dormer
Mayfair typical
£143k£221k
Semi-detached / end-of-terrace. Maximum floor area gain.
Mansard
Mayfair typical
£169k£286k
Rear roof replaced. Premium choice for period houses. Full planning.
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The 2026 London Loft Cost Guide.

Borough-by-borough pricing, a full cost breakdown, PD vs full planning explained, and the seven hidden costs to watch for in Mayfair and beyond.

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Mayfair loft FAQ

What Mayfair homeowners ask us.

Do I need planning permission for a loft in Mayfair?

Mayfair Conservation Area, with overlapping Hanover Square, Conduit Street and Berkeley Square conservation areas. A high listed-building density. Outside conservation areas, most rear-dormer conversions in Mayfair qualify for permitted development (PD) within the 40m³ (terrace) or 50m³ (semi/detached) volume limits. Mansards always need full planning. We check your specific address before quoting and submit the application on your behalf.

What scale of loft project is typical in Mayfair?

Mansards on Georgian terraces are the norm, with budgets typically £250k–£500k all-in. Listed-building consent is required on most properties, and the design phase often runs 6–9 months. Mews properties are usually simpler — single-storey rear-roof additions with skylights.

How long does a Mayfair loft conversion take?

Typical timeline: 6–10 weeks for design and planning (longer in conservation areas like much of Mayfair), then 8–14 weeks on site for a standard dormer, 12–18 weeks for an L-shape or hip-to-gable, and 14–20 weeks for a mansard. City of Westminster processes PD-route Lawful Development Certificates in approximately 8 weeks.

What does a loft conversion add to Mayfair property values?

In W1, a well-executed loft conversion typically adds 15–25% to property value — often more in prime postcodes. The ROI is strongest when you add a double bedroom plus en-suite, which is the standard L-shape dormer configuration. Property uplift on a £59k–£286k build commonly exceeds the build cost by 30–60%.

Does 2VP work on Mayfair loft conversions?

Yes — Mayfair is within our core London catchment. Our studio is at 20 Dawes Road in Fulham, 5.5km from Mayfair. We've delivered loft conversions across the W1 postcode and our subcontractor network covers Westminster. Free site visit, itemised quotation, 12-month workmanship warranty on second-fix fittings on the finished work — with an optional 10-year HomePro guarantee on request, arranged with HomePro and paid directly to them at 2.5% of the contract value.

Nicholas Elias RIBA
Vladimir Castravet
Free site visit · Mayfair

Twenty minutes on site in Mayfair.
On us.

Nick Elias RIBA and Vladimir will visit your Mayfair home, walk the loft, check head height, advise on PD vs planning, and give you a realistic budget and programme — even if a loft isn’t right for your house.

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If this is your project

The home you actually want, finished on the date in the contract — and you watch every day of it happen from your phone.

How fast
  • Your number in 60 seconds
  • Itemised stage breakdown in 2 minutes
  • Survey within 7 days
What you do

You answer 3 questions. We do the drawings, planning, party wall, trades and snagging.

What protects you
  • 10% to mobilise, then weekly against work already done — with 5% held past handover: 2.5% released at practical completion and 2.5% at the end of the 12-month defects period
  • £550 survey fee credited in full against your contract
  • Every variation priced and signed before a penny is spent

The date is a term of the contract. We finish on the agreed date, or we pay you £500 for every week we are late.

Do not take our word for it

4.8 from 16 Google reviews

Every review is published in full on our reviews page, including the one-star. Google is the only platform we quote a rating for, because it is the only one we can evidence.

★★★★★
As a structural engineer, I've collaborated with 2VP Projects Ltd on several residential projects in London. Their attention to detail, proactive site management, and clear communication make every stage—from design to execution—smooth and efficient. It's rare to find a contractor who values both precision and professionalism at this level. A truly reliable partner.
Igors Smirnovs · Structural engineer we have worked with · June 2025
★★★★★
Great company to work with. Professional, reliable and easy to deal with. Vladimir and the team are always responsive, straightforward and genuinely care about doing things properly. I've had a very positive experience working with 2VP and would happily recommend them.
Sheen Delicatessen · Business client · August 2026
★★★★★
Extension went smoothly from start to finish. Communication was great throughout, and the team delivered exactly what we asked for. Thank you, 2VP!
Dan Martea · August 2026
Warranties and protections

What is covered, and by whom

A builder’s own guarantee is worth exactly as much as the company standing behind it. Here is what comes as standard, what you can add, and what has to come from somebody other than us — set out in full on our insurance and guarantee page.

Included in the contract
  • 12-month workmanship warranty on second-fix fittings
  • £5M public liability
  • £10M employer's liability
  • £2M professional indemnity
Optional, on request
  • HomePro insurance-backed guarantee, 10 years
  • Priced at 2.5% of the contract sum
  • Underwritten by an insurer, so it survives us
Not from us
  • 10-year structural warranty on a new dwelling (NHBC / LABC / Premier)
  • Professional fees — architect, engineer, building control
  • We will tell you when you need one rather than let you find out