One Berkeley Street

The Brief

The scheme sees the refurbishment and extension of an existing 1970s building in Mayfair which fronts onto Piccadilly, Berkeley and Dover Street. The Client’s brief is to create a ‘destination’ mixed-use development containing hotel, office and prime retail space. Although planning permission was granted to demolish and rebuild the site the Client decided to proceed with a design that retains 90% of the existing structure as well as the facade along the two main elevations.

We acted as Project Manager through the pre-construction phase together with the CDM Client Advisor (CDMA) and Principal Designer (PD) roles, both of which we continue to provide.

Having acted in both roles for the soft strip and demolition phase and for the shell and core phase, we are now appointed as CDMA and PD for the hotel fit out and separately for the annex building fit out, which will become the Client’s new office space. We’re also acting as PD for the highways and logistics packages.



Crosstree Real Estate Partners


London W1


210,000 ft²


  • Hotels
  • Office - Remodelling & Refurbishment
  • Retail


  • Project Management
  • Health & Safety (CDM)

The Challenge

The retained concrete frame structure had been built over a number of years as the original building was adapted and expanded. There was very little record information about the frame and extensive investigation works were required which had to be undertaken whilst the existing hotel and office areas remained in use. Given the age and construction of the building asbestos was expected but the extent found meant that its removal was far more challenging than first expected.

The restricted city centre location posed a number of logistical challenges for the team and contractors. Reviewing these issues and identifying options as to how to deal with them both at pre construction and throughout the construction period was a major topic and consideration throughout our coordination meetings and the subject of intense scrutiny by the CDM team. Additionally the site’s location made future access and maintenance a challenge; as Principal Designer we worked with both the design team and an external access consultant to identify a practical and economic solution to these issues..

The Client relied heavily on our advice and coordination of the six principal contractors who are appointed to complete different sections of the scheme. This posed a challenge for our team in ensuring that there was a clear demarcation between the work areas for the contractors as well as detailed and well defined communication and coordination protocols.

The Outcome

Once completed, the existing buildings and retained pedestrian through-access link will have been expanded with the addition of three new extensions: a two-storey rooftop extension, new pavilion at the corner of Dover Street and an annex building within Dover Yard. The Yard itself will be transformed from a parking and delivery space into a garden courtyard and the entire façade will be rejuvenated. The new luxury hotel – 1 Hotel Mayfair – will have 181 guestrooms, 20% being suites located mostly on the newly built eighth and ninth floors and offering views over Green Park.

We have provided valuable advice for both the client and principal contractors, our regular site inspections highlighting areas for improvement in health and safety standards. Working with the design team, we have provided support to ensure that the designs fully address CDM issues, in particularly buildability and future maintenance.

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Other Projects We’ve Completed Include

Goodenough Hotel

Cheval Phoenix House

The Ryder Hotel