Skip to content
CLW
11-12 St James's Square, Foster & Partners scheme for the Ellison Institute of Technology

Project case study

11-12 St James's Square

RIBA Stage 3 waterproofing design philosophy for the basement development at 11-12 St James's Square for the Ellison Institute of Technology, with Foster & Partners as architect.

11-12 St James’s Square is a basement development for the Ellison Institute of Technology, Oxford Limited, with Foster & Partners as architect, Heyne Tillett Steel as structural engineer and Ridge & Partners as project manager. CLW was commissioned as the waterproofing design consultant to provide the RIBA Stage 3 waterproofing design philosophy.

The project includes buried deck and podium elements and specifies Type A, Type B and Type C protections to achieve Grade 3 and Grade 2 waterproofing performance, with particular emphasis on heritage fabric preservation. On a St James’s Square site, the heritage constraint is not a footnote, it shapes what the structure can accept and therefore what the waterproofing strategy can rely on.

CLW worked closely with Foster & Partners and Heyne Tillett Steel to develop a coordinated and resilient waterproofing strategy, set down at Stage 3 so that the grades, system types and interfaces are fixed before the design moves into procurement.

Image credit: Foster & Partners.

Working on a comparable scheme?

Independent waterproofing design from RIBA Stage 2 through construction monitoring. Defensible, document-led, contractor-agnostic.