The existing building is a seven-storey 1950s in-situ cast reinforced concrete frame with beam and clay pot floors. Being a new high-end retail store the ground floor area is of optimum value so the reduction of retail space for stair access to a first floor was not efficient. Therefore, the decision was taken to remove the first floor slab to create a dramatic new space with exposed steel frame. Structurally, it was challenging to sequence the work and ensure they may be reversed at the end of the lease.