The trendline: office-to-hotel conversion
"When one door closes, another opens" is a quote often attributed to Alexander Graham Bell. In London, we see this play out as low-quality, obsolete office spaces are given new life as much-needed hotel space. Our co-founder Gerry O’Brien reflects on his experience and suggests that this trend is really nothing new!
The 'flight towards quality' in the London office market has been a topic of discussion for years, and leasing trends clearly confirm this. As employers vie for the best talent, they use the office to demonstrate their commitment to combatting climate change. They lease high-quality, low-energy workspaces near low-carbon transport hubs.
To deliver high-quality workspaces and meet tightening regulations, developers face significant capital costs. They need to recover these costs through higher rental rates (£/sqft), which invariably must be supported by an increase in net lettable floor area. Adding area is not always possible. Constraints like rights of light or planning envelopes limit expansion above ground, while costs and utilities restrict expansion below ground. Consequently, many city centre buildings face potential obsolescence as offices because they cannot compete.
It is no surprise that landlords consider new uses for these assets, such as city centre residential. Recently, there has been a significant surge in office-to-hotel conversions. This topic is making headlines, but the trend is nothing new; we have been doing this for decades. The results can be outstanding, though my experience shows it is often not without challenges.
Giving a second life to tired 1960 office blocks
My experience in converting offices to hotels started in 2012. 4C Hotels acquired three tired 1960s buildings near St Paul’s Cathedral, with planning permission to demolish them and create the new 5-star Queen Hithe Hotel. The project included nine apartments in a neighbouring riverside residential block.
Studio Moren was appointed to take the project forward. They developed designs that reused the existing bridge structure to house public areas, four floors of guestrooms, and a plant deck, along with the necessary structure, and mechanical and electrical systems. As the existing office floor-to-floor heights were unsuitable, the upper floors were removed and replaced. Substructure elements for the buildings on either side of the bridge were also reused, including existing retaining walls and piled foundations on the north side of Upper Thames Street.
The project was structurally complex as intrinsic elements formed part of London’s strategic flood defences. The condition of the existing bridge crossing Upper Thames Street was as critical to the City of London’s traffic operations as it was to the hotel owner and operator; this required extensive investigations. Furthermore, the development had to be physically separated from the Queens Quay apartments at 58 Upper Thames Street, which were built at the same time as the three 1960s office buildings.
The optimal space planning for the hotel on the bridge was slightly rotated relative to the plan of the existing structure. The columns supporting the upper floors had to sit on the existing concrete bridge beams, creating an asymmetry that produced a lateral sway load under vertical loads (self-weight and live loads). This required a refined construction approach to avoid overloading the beams.
Once the hotel operator was on board, 4C Hotel Group appointed Vascroft to construct the project to Studio Moren’s designs. The Westin London City was successfully delivered in October 2021, concluding the conversion of an existing office building into a new 10-storey, 222-bedroom luxury hotel. The development includes nine high-end apartments, a swimming pool, a gym, and a wellness centre positioned above the preserved Roman baths.
Turning dated 1970s workspaces into mixed-use hubs
At around the same time, 4C Hotels acquired a site in Aldgate that had become known as the 'Trinity Site'. The name came from a planning permission obtained by Foreign Office Architects for the Beetham Organisation. Their design for three crystal-like buildings required the demolition of all existing assets. When Bashir Nathoo called me to ask if we would like to be involved, I asked how he managed to secure such a commercially hotly contested site, and he told me that others wanted the site, he wanted the buildings. It was perfect to convert to a hotel and get back on stream quickly; a vision now playing out in many parts of the city.
Bashir was right. The office building on site was arranged with two offices on either side of a central spine corridor. Changing those spaces to hotel rooms rather than offices would be relatively straightforward. However, as the design team began to examine the site, things became more complicated. It became clear that there was a lot of latent value beyond the hotel, but accessing it would require some structural gymnastics.
Acme designed and delivered a mixed-use scheme for the entire site, comprising a refurbished hotel, a new office building, and a residential block. The scheme also features a landscaped park around the residential building and urban squares with landscaping and seating areas. Shops and business units occupy the ground floor alongside the office building.
For the hotel to be successful, its front door had to be on Minories. This was problematic as this location was the access point to the service yard and basement. To create a new access route and a service yard capable of servicing the hotel, 84 residential properties, 18,200m2 of office space, and a central energy centre, it was necessary to demolish one of the existing buildings.
The retained building, 16 Minories, was constructed between 1977 and 1981 as one of two abutting office buildings. The frame consists of reinforced concrete slabs and structural columns, both of which are exposed on the facade to create a consistent 1.5m grid. A structural assessment revealed a low degree of carbonization and satisfactory loading capacity, with scope for further extensions. The building has no insulation on the outside or inside.
The neighbouring building at 15 Minories was of similar construction, but structural assessments revealed a high degree of carbonization and structural flaws, meaning it could not be retained and had to be demolished.
A new block, rotated in planform from the original building, was constructed with transfer structures to allow access to the large service yard below. Although the project was delivered in phases (hotel, residential, then office), the substructure works for the entire site were grouped into a complex demolition and enabling package that was carried out by Morrisroe. This package included the foundations for the residential block and a temporary piled wall that was later removed to provide access to the office basement during its construction.
The main contract was awarded to Radford Group and X Construct to realise Acme’s designs and deliver London’s first Canopy by Hilton.
Transforming a historic landmark for a new era of luxury
Perhaps one of the most challenging high-profile retrofit / conversions is The Chancery Rosewood in Grosvenor Square. While this project stretches the boundaries of those definitions, it shares key characteristics with the previous two examples: it was an obsolete office building in the right location, and in need of some really clever engineering to make it all work.
David Chipperfield Architects designed the project for Qatari Diar, who acquired the site from the US Government after the embassy relocated to Nine Elms. Following the grant of planning permission, a hotel operator was secured, and the designs were thoroughly scrutinised before construction contracts were placed.
In 2018, Careys was appointed to a highly complex enabling works package. This involved installing a new embedded retaining wall to create a four-storey basement in place of the original 1.5-storey structure. Throughout the process, the retained elements of the existing building structure and facade were supported on temporary trusses and piles, allowing the new basement to be constructed beneath them.
With work well underway, Multiplex was appointed as the main contractor in December 2020. As the basement structure was built upwards, it effectively 'picked up' the retained building, with the loads being jacked onto the new permanent structure.
Huge transfer trusses were installed within the basement to create space for one of London’s finest subterranean ballrooms, alongside sumptuous spa and fitness facilities.
This magnificent hotel finally opened in 2025 to widespread acclaim, marking another successful chapter in London's history of reimagining its built environment.