A new build mixed use development on an extremely confined site in Brixton, 374 Cold Harbour Lane comprises 10 apartments across two storeys along with two storeys of commercial space in a concrete and steel frame building.
To maximise the footprint of the site while complying with right to light planning requirements, the building includes a basement level and was designed with a curved structure, which maximises the floor area while allowing sufficient natural light to reach neighbouring properties. This answered planning, unit size, commercial and aesthetic requirements, but involved buildability challenges. These were addressed through design development and meticulous project management from the Edgeley Construction team, with just a 1.5m wide walkway to access the site thanks to negotiations during the pre-construction phase to borrow land from the neighbouring property for the duration of the project.
To create the basement level, the Edgeley Construction team excavated around 3,360m3 of soil, which had to be removed via the heritage building at the front of the site, which was converted as part of the same project.
The building’s concrete frame provides the floorplate structure for each level, while the steel frame that rises from ground level to roof creates the structure for the curved elevations and the roof, with outset dormas and inset balconies allowing maximum internal useable floor areas as the building rises.
Thanks to the curved structure, the roof continues down to the side elevations of the building and a roofing system that could extend from the façade up to the flat roof was required. The Edgeley team developed the architectural design to enable the use of zinc cladding for the whole of the curved area, designing the façade to enable the use of four different types of HPL cladding system, involving the complex interfacing of materials for the vertical elevations. A double layer of thin ply was used to create the curve, followed by insulation and helping hand brackets. The team then installed an additional two layers of ply, leaving a 50mm ventilation gap, before installing the zinc, which was malleable enough for the team to mould it to the contours of the structure.
The roof area also included AOVs, rooflights and solar PV panels, which required a significant amount of detailing from the Edgeley Construction team.
The building includes further roof areas on the box-bay floor-to-ceiling windows at ground level and 1st floor, which, as Axter approved installers, we waterproofed using an Axter reinforced bitumen membrane, was colour-matched to the zinc cladding.
Edgeley Construction was responsible for both the build programme and fit out of the property, which was achieved to a very high standard and mission-critical deadlines. The project was delivered with a sectional completion, involving handover of the residential levels first, followed by the commercial accommodation.