This is Brunswick House now overshadowed by the St Georges Wharf Development. It is a listed Georgian mansion and former home to the Dukes of Brunswick. It was originally set in 3.5 acres of park land but that has long since gone.
The building was on the English Heritage 'Buildings at Risk' list but it has since been restored by the London Architectural Salvage and Supply Company (LASSCO). The premises now sells architectural salvage and has a cafe.