Theis + Khan Architects created additional space for a family living on the top floor of a Victorian warehouse
The roof-level, steel-framed extension houses a sitting room, bedroom and shower room, allowing the existing floor below to be reorganised. The frame extends around the roof terrace creating an enclosure, while a new staircase is a sculptural focus for the lower floor. Finishes are simple, with white-painted plaster and brickwork, hard-wood flooring, timber decking and rough-sawn timber external cladding and a sedum-planted roof.
Architect’s description of staircase detail
The staircase is a dogleg with winding treads on the turn. It sits over an existing straight staircase that provides access to the flat from the common hall, and connects the main living area on the third floor with the new roof extension.
The existing staircase, which was part of the common hall and was partitioned off, has been absorbed into the flat by relocating the entrance to the bottom of the flight at second floor level, and replacing the partition with a balustrade wall. This has allowed the returns of the existing L-shaped living area to be visually linked, with the new staircase as its focus.
The staircase is effectively hung from the steel trimmer on the top landing, with a bearing on the steel trimmer at the bottom. It is formed from 12mm steel treads, welded to curved 250 x 25mm steel stringers. Steel uprights of 25 x 25mm welded to the stringers form the framework for the slim, painted balustrade walls.
Click on the image below to see plans of the project as a pdf
The original detail shows the staircase balustrade wall connected to the returns at the lower level, along the edge of the existing straight flight below, forming a continuous ribbon. After it was constructed, we felt that the curved balustrade returns looked heavy, so we decided to cut them out and separate the two elements with just two steel rods to provide stability.
Patrick Theis, director, Theis + Khan Architects