Project case study
Holden House
Waterproofing design for the basement levels of the Holden House refurbishment, Westminster.
Holden House is a Westminster refurbishment in which the existing below-ground levels were brought back into commercial use. CLW was appointed to deliver the waterproofing design for the basement.
Refurbishment of an existing basement is a different design discipline to new build. The existing structure, the existing waterproofing condition and the existing service penetrations all set constraints that a new-build performance specification simply cannot anticipate. The strategy was developed under BS 8102:2022, with risk assessment grounded in what the structure actually was rather than what a clean-sheet design would prefer it to be.
The commercial value point on a refurbishment of this kind is restraint, selecting the system that the existing structure can actually support, rather than over-specifying against a condition that will never be achieved.
Project credit: —.
Working on a comparable scheme?
Independent waterproofing design from RIBA Stage 2 through construction monitoring. Defensible, document-led, contractor-agnostic.