The challenge

The Pelier Street development delivers 17 council homes for social rent as part of Southwark Council’s programme to increase affordable housing across the borough.

Located on a constrained brownfield site close to Pelier Park and the main railway line into Elephant and Castle, the development required a roof design capable of balancing waterproofing performance, sustainability and environmental integration within a dense urban setting.

The project brief required the roof to contribute to biodiversity, support renewable energy generation and form part of the building’s sustainable drainage strategy while meeting the performance requirements expected of a residential development.

The approach

Langley developed a roof specification combining the TA-20 Flat Roofing System with photovoltaic panels and a biodiverse roof build-up.

The TA-20 system was installed by Langley Approved Contractor Aldworth Roofing Contracts directly onto the concrete roof deck. Tapered insulation was incorporated within the build-up to assist with roof drainage.

Above the waterproofing layer, a biodiverse roof system was installed consisting of a specialist growing substrate, river-washed cobbles and a wildflower seed mix designed to support urban biodiversity.

The roof specification also incorporated photovoltaic solar panels to generate renewable electricity for the building.

Together, the biodiverse roof and photovoltaic installation contribute to the building’s environmental strategy and assist in managing surface water run-off.

The outcome