CASE STUDY | THE OWO HOTEL Luxury awaits Transforming the 1,000-room Old War Office building in London into a luxurious Raffles hotel has been a momentous project for Aecom engineers. Andy Pearson discovers that an extensive services refit did not detract from the magnificence of the makeover F rom seat of power to one of Londons most luxurious destinations, the Old War Office building in Whitehall, London, has undergone a monumental six-year transformation. The Grade II* architectural landmark, the corridors of which were once walked by Winston Churchill, will open its doors to the public this autumn, transformed into a flagship Raffles hotel. Known simply as The OWO, the hotel has 120 rooms and suites (known as keys in the hotel industry) and includes nine restaurants, three bars, and 85 Raffles-branded private residences. Built in 1906, the listed buildings metamorphosis from government office to leisure destination has resulted in the already colossal, 1,000-room structure being extended by 31% with the addition of a three-storey rooftop extension. There are also four additional basement levels carved out below the Baroquestyle edifice to house a spa, swimming pool, ballroom and kitchens. It is the scale of the project, its location within the Whitehall conservation area, and the need to sensitively restore and preserve many of the buildings historic interiors that have made servicing the new hotel a herculean task. It is all about coordination and trying to get services around the building without disturbing all of its beautiful features, says Anthony Hume, technical director and The OWO project manager for building services engineer Aecom. 34 October 2023 www.cibsejournal.com Hume has been involved with the project since 2017, when Aecom was asked to look at the services in the former office building with a view to it being turned into a luxury hotel. That was the easy bit; the scale of the project is so big it meant nothing could be reused, so the whole lot needed to be stripped out to enable us to start from scratch while respecting the listing, he says. Aecoms approach has been to service the building as a whole, with dedicated systems for each building the hotel and high-end residences where possible The hotel has the larger footprint. Its 120 guest rooms occupy Levels 1 to 6, while amenity spaces, restaurants and bars make up the ground floor, and the subterranean ballroom and its associated kitchen are at Basement Level 2.