A substantial refurbishment of a Grade II listed town house in Belgravia, including the demolition of a mews property and construction of a new double basement over the back of the site.
Demanding ground conditions included water bearing gravel at formation level. Several basement construction techniques were investigated including CFA piling, sheet piling, underpinning and permeation grouting to the perimeter. Detailed discussions and geotechnical analysis led to successful consents from Grosvenor, Westminster Conservation and Party Wall surveyors for a solution which maximised basement size by using a combination of underpinning and Giken zero piling to form the basement retaining wall.
The reinforced concrete basement box supports a lightweight hybrid steel and concrete structure over, minimising floor construction depths. Significant alterations were also undertaken within the main house.
Client: FinchattonArchitect: Lifschutz Davidson Sandilands