Interior photograph of Substation No. 175, Surry Hills featuring the interior of the upper apartment.

Substation No. 175, Interior upper apartment. Photo (c) Brett Boardman.

Micro-housing: Substation No. 175

Focus Tour - Saturday 2 November

Surry Hills




City of Sydney - City architect


2005 AIA (NSW) - Commendation for Multiple Housing

2005 Master Builders Associations – Excellence in Housing Awards, Adaptive Reuse over $500 000

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. The 4.8m x 9m site now holds a street-level cafe and two residential apartments. The project is a model for appropriately scaled infill development, serving as a demonstration of the benefits of compact city planning principles.

Situated on a 44-square-metre plot at the southern edge of the city, the substation sat mutely within an eclectic urban context of low-scale terrace housing to the east, a 15-storey commercial slab tower to the north, and a pocket park to the west. A lightweight, zinc-clad addition was grafted onto the substation building, transforming the redundant industrial shell into a miniature city tower. The key structural challenge was dealing with the slenderness ratio of the building while satisfying the earthquake code. In order to provide sufficient stiffness to the structure, the lower three floors are a reinforced concrete frame. The frame is fireproof and stabilises the retained brick perimeter walls. For lightness and speed of erection, the upper three floors are a steel frame.

Tour experience

The tour allows visitors to experience one of Sydney’s unique small-footprint developments. The mix of a cafe and two different apartments intensifies the use of the site, showing that no lot need be too small to be used efficiently. The design strategy retains most of the existing substation structure, and builds above a new structure of equivalent volume.


Philip Thalis

Philip Thalis is a well known architect, director of Hill Thalis, current City Councillor, Professor of Practice at UNSW and former HHT Trustee.

  • Exterior photograph of Substation No. 175 in Surry Hills featuring building's western facade at dusk.

Key information

Session duration

45 mins


This tour has a capacity of 20 people per session.

Visitor requirements

All guests must be able bodied and physically fit. The building contains six storeys of tight stairs with no lift available.

to know

  • Photography allowed

  • Please note that there are 6 storeys of tight stairs & no lift available.