Originally completed in 1925, Substation No. 175 was a small face-brick building housing oil-filled transformers for the City of Sydney’s power supply until its decommissioning in 1996.

This intervention grafts a lightweight zinc-clad addition onto the substation shell, transforming a redundant industrial relic into a miniature city tower. The 4.8m x 9m site now holds a street level cafe and 2 residential apartments over 6 storeys.

A tightly-coiled promenade architecturale forms a richly layered sequence of spaces. Stairs and circulation spaces are strategically located to dramatize the experience of moving vertically through the building. Habitable rooms have dual orientation, addressing both the park and street frontages while maximizing light and ventilation to the interiors.

A carefully calibrated pattern of windows and zinc panels presents a new urban facade to the pocket park. Counter to the profligate land use characteristic of low density Australian cities, this project intensifies the use of its tiny site, showing that no lot need be too small to be used effectively.

The building was published in the Australian Architecture Review Residential Special 2005 and the Domain supplement of the Sydney Morning Herald. The project has been featured in a Focus Tour in the 2004 Sydney Open Program run by the Historic Houses Trust, Australian Architecture Association tours and an Institute of Architects houses tour.