Broadway House, Wimbledon is a 7 storey new build mixed use development consisting of 86 apartments, 12,000 sq ft of retail and 42,000 sq ft of office accommodation over a basement carpark.
A number of engineering options were considered at the early design stage and an exercise was carried out to compare the merits of a post tensioned in-situ concrete frame solution with a traditional in-situ RC frame and slab solution. As a result of this exercise, a decision was made to progress with the traditional concrete frame – RC columns and walls supporting RC flat slabs.
The columns have been set out such that they continue down to basement and achieve the desired number of car park spaces – this avoided the requirement for transfer structure. In the apartments, 215mm wide RC columns are hidden within the partition walls and support 250mm deep RC Flat Slabs. In the office and retail spaces, circular columns are set out on a 7.5m grid. The cladding consists of brickwork, render and timber panels fixed back to a lightweight Metzech frame. Due to the high water-table levels around this site, a contiguous piled wall with an internal concrete wall finish was constructed around the perimeter of the new basement. This piled was designed to act as a free standing cantilevered wall with no props in the temporary case to facilitate construction.