Project Description

A new theatre development offering two new auditoriums, flexible rehearsal spaces, and a vibrant café and mixed-use office space. The project also included the renovation of Carlton Mansions into office space. The site of the project sat directly above a Victoria Line train-reversing tunnel, posing serious structural challenges. The layout of the underground tunnels mitigated the use of piled foundations and a ground—bearing raft was chosen. To balance the existing load on the tunnels and the loads imposed by a new six-storey theatre, an under croft was constructed to reach safe bearing strata.

Judge’s comments

This technically complex project, required the engineers to work over and around some of London's most heavily used Underground Railway infrastructure, necessitated a painstakingly careful assessment of ground movements and deflections, as well as more familiar structural engineering techniques of building stabilisation and restoration work on a highly confined site.

The reuse of the culturally significant Carlton Mansions building as part of the new scheme assisted in significantly reducing the embodied energy statistics for the overall project, as well as mitigating the risks.

Project overview

Structural Designer

  • Conisbee

Client Name

  • London Borough of Lambeth / Brixton House Theatre


  • London, UK


  • Foster Wilson Size LLP / Zac Monro Architects

Principal Contractor

  • Galliford Try Construction Ltd.

Key Contractors

  • Dodd Group  – Mechanical and Electrical Engineer 

    Charcoal Blue  –Theatre Consultant

    Geotechnical Consulting Group – Geotechnical

    Capita – Project Manager

    Tibbaulds Planning & Urban Design – Planning Consultant

    Mifflin Construction Ltd. – Steel Fabricator

Year Submitted

  • 2022

Key attributes

  • Process