Mayfair Townhouse Restoration Shortlisted at the Mix Awards 2026

A Grade II listed Georgian townhouse in Mayfair, transformed into a modern workplace for a global private equity firm, has been shortlisted for one of the UK’s most prestigious interior design awards; and we’re proud to have played a part in it.

6 Upper Grosvenor Street has been named a finalist at the Mix Awards 2026 in the category of Project of the Year: Workplace Interiors (5,000–10,000 sq ft), placing it among the finest office interiors completed in the UK this year.

The Project

The brief was an ambitious one. The client; a global private equity firm specialising in scaling software and data businesses; needed a London headquarters that would stand out within its international portfolio. The building they chose, a Grade II listed Georgian townhouse in the heart of Mayfair, offered the right address and the right character. The challenge was making it work as a high-performance modern workplace without losing either.

Across 7,300 sq ft and 43 weeks, that’s exactly what was delivered. Original timber floors, shutters and vaulted ceilings were carefully restored by specialist craftspeople, while advanced building services and integrated technology were threaded discreetly through the historic fabric. A grand reception and client suite set the tone on arrival, with open office floors, meeting rooms and a dedicated gym beyond.

Heritage and Performance, in Balance

What made this project genuinely interesting was the tension at its core. Listed building constraints, heritage approvals and structural upgrades all had to be managed in sequence alongside the demands of a sophisticated client operating at a global level. The scale of coordination required was significant; but programme and cost were kept firmly under control throughout.

The result is a headquarters that feels both rooted in its surroundings and entirely fit for purpose: a rare combination in any building, and a particularly difficult one to achieve in a listed structure on one of London’s most historic streets.

Bonavia’s Role

Bonavia Ltd provided quantity surveying services throughout the project, playing a central role from the earliest stages of procurement through to final account. During the Pre-Construction Services Agreement period, Bonavia worked closely with the design and delivery team to develop and interrogate the cost plan, ensuring the scheme remained commercially viable as design detail was established. This included benchmarking against comparable heritage and listed building projects, stress-testing key assumptions, and identifying areas of cost risk inherent in working within a Grade II listed structure in central Mayfair.

As the project moved towards contract, Bonavia led the contract sum negotiations, working to reconcile the contractor’s pricing against market rates and the specific demands of the project. Particular attention was given to the specialist and heritage elements of the works — areas where pricing can be difficult to validate and where inadequate allowances can create significant exposure later in a project. Bonavia also advised on the contract terms and conditions, ensuring the chosen form of contract appropriately allocated risk between the parties and that the client’s position was protected across key areas including change management, programme obligations and defects liability.

The result was a contract entered into with confidence on both sides — a foundation that supported a collaborative working relationship and helped deliver the project on programme and within budget.

Recognition at the Mix Awards

The Mix Awards, run by Mix Interiors, are widely regarded as a benchmark for excellence in UK workplace design. Being shortlisted in the 5,000–10,000 sq ft category is a reflection of the quality of thinking and craft that went into every part of this project.

The awards ceremony takes place in June 2026. We’ll be watching with interest.