Under Construction

1 Mayfair

1 Mayfair is the largest residential development in London's Mayfair, an ultra-prime scheme by John Caudwell's Caudwell that occupies half a city block around a central garden.

Official Website
TMW IntelligenceVerified Sep 27, 2026
AnnouncedBreaking GroundConstructionOpening SoonNow Open
2020
Start
~2027
Completion
29
Units
9
Floors
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Details

5 Audley Square, Westminster. 9 floors and 29 residences. Broke ground 2020, targeting 2027.

The story so far
Announced 2020 est.
Broke ground 2020
Topped out Dec 4, 2024Topped out per Show House / Caudwell, 2024-12-04; £2bn GDV, ~300,000 sq ft, completion now Q1 2027
showhouse.co.uk
Tenant announced Oct 20, 2025Dorchester Collection named residence manager; completion now targeted Q1 2027 (Boutique Hotel News)
boutiquehotelnews.com
Heywood Hill appointed to curate 1 Mayfair's private library Mar 2026Caudwell commissioned the Mayfair book dealer owned by the 12th Duke of Devonshire to assemble more than 1,000 volumes and objets for the library at the £2 billion scheme, whose 24 principal residences and five pieds-a-terre make up the 29 homes around the central garden.
spearswms.com
Expected opening 2027 est.
Milestones are dated to when they actually happened and linked to their source. This record fills in over time as TMW tracks the project.
Supply pressure 49 · ElevatedLondon marketMarket →
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About the project

1 Mayfair is the largest residential development in London's Mayfair, an ultra-prime scheme by John Caudwell's Caudwell that occupies half a city block around a central garden. Designed by Robert A.M. Stern Architects, it comprises a collection of principal residences, penthouses and townhouses alongside pieds-a-terre and grand entertaining spaces, with resident services to be managed by Dorchester Collection. A vast basement excavated deep below ground houses a health spa with a twenty-metre swimming pool, parking and hotel-style amenities, positioning 1 Mayfair among the most valuable residential addresses in the capital.

Developer & design
The London market 49 · Elevated supplyMayfair 32-project pipeline · 22,043 residences and keys · peak Late ’28 Explore the market →
Common questions

Frequently asked

Where is 1 Mayfair located?

1 Mayfair is located in London.

When will 1 Mayfair be completed?

1 Mayfair is under construction, with completion expected in 2027 (a TMW estimate).

Who is developing 1 Mayfair?

Caudwell is the developer behind 1 Mayfair.

Who designed 1 Mayfair?

1 Mayfair was designed by Robert A.M. Stern Architects.

How big is 1 Mayfair?

1 Mayfair rises 9 stories with 29 residences.