Basement extension beneath a large Victorian house in Kensington, founded in gravels into the water table over a deep clay layer.

Eckersley O’Callaghan carried out extensive refurbishment works on this four-storey Victorian masonry building in Kensington. To create a new basement, the building required temporary support of its existing internal structure on a system of reinforced concrete underpin beams and piles. External and party walls were underpinned in two levels as excavation progressed. Meanwhile, adjoining piles were used as temporary retaining walls for excavations outside the footprint of the building. A new watertight reinforced concrete box was then constructed underneath. 

The building shares a party wall with a neighbouring house, and particular care was needed to control any movements of the fragile masonry during construction. 

Much of the upper internal fabric of the building was then rebuilt or repaired as part of the works, together with extensive remodelling and repair of the external envelope to stabilise and conserve the building for the future. 

Location
Kensington, London, UK

Client 
Private

Architect
Seth Stein Architects