1-4 Marble Arch is a high-specification development of a new retail and commercial building in the heart of London’s West End. The structure boasts three floors of retail space and a further seven floors of high-quality Category A office space. Combining a retained 1920’s façade with a modern interior, it sits directly opposite the Marble Arch monument.
Development was undertaken within the Grade 2 listed façade located on Marble Arch and Great Cumberland Place elevations with a view to protecting the city’s historic streetscape. The existing steelwork façade was retained up to and including level 6, with a demolition and rebuild taking place behind it.
Based on a regular column grid pattern of 6.5m x 9m stabilised by a single concrete core, Bourne’s steel frame supports metal decking with a concrete topping to create a composite flooring solution for the new 10-storey building. New steelwork connects to the retained façade steel columns via bolted connections and supports the old structure.
The majority of the structure’s steel beams are fabricated plate girders with bespoke cells to accommodate the building’s services within their depth. Soffits have been left exposed within the completed building, along with the steelwork which has a high decorative intumescent paint finish to the beams and columns for a modern industrial inspired finish. The offsite application of the paint systems greatly reduced onsite works as there was only a need to undertake repainting to the connections and a few knocks and scratches that occurred during construction. New fenestrations have also been added consisting of slimline steel windows.
Flexibility is at the heart of the design, as each office floor can be occupied by a single tenant or sub-divided into two. Level one, initially designed as the upper retail floor, can be changed into office space if required.