Northfields Station Architect: Charles Holden & Partners, 1932 The first station opened here in 1905, on the District line, but the present building was constructed as part of the 1930's extension of the Piccadilly line that helped fuel the suburban growth of this once rural part of London. Holden's impressive building takes the form of a single storey plinth, which contains offices and shops, and is faced in black glazed brick. The tall brick box that forms the ticket hall has a window that includes the Underground roundel. The design continues down to platform level, where extensive use is made of concrete, which at the time was a novel concept.