1-5 Kingsway is an existing 10-story Victorian steel and load bearing masonry building in the West End of London. The sight is on a prominent corner of Kingsway and Aldwych and is part of the Strand conservation area.
This project consists of a structural design for mixed-use retail, office and executive residential apartments behind a retained façade. In addition to the technically challenging façade retention in a sensitive area, the project is adjacent to an existing road tunnel which restricts positioning of the temporary works to the elevation.
The site is bounded on three sides by public highways and a party wall on the fourth boundary rendering it a very restricted inner city site. An innovative and compact structural solution was therefore required to take into account the retained façade on two elevations, adding further complexities to an already restricted site.
The new build structural depth is also limited to ensure the new floors align with the existing façade while maximizing the number of lettable floors in the building. This problem was overcome by designing a thin structural floor plate depth of 260 mm spanning up to 7.6 meters. A post-tensioned concrete flat slabs and ultra-slim floor beams (USB) were both considered as viable structural solutions to address the constraints of minimal structural floor depths. The post-tensioned concrete option was selected as the most cost effective overall. Part of the project scope also includes adding two further floors to the original building.
This development was awarded an Excellent BREEAM rating for the design stage.
Location: London, United Kingdom
Owner: UKI (Kingsway) Ltd
Architect: Sidell Gibson
Area: 9,600 m²
Completion Date: 2011