One40 William

Design Feature
Type of Project
Western Australia

The development of One40 William Street, Perth is an excellent example of mixed-use and transit oriented development. The office, retail and entertainment land uses are supported by pedestrians accessing Perth's Underground Train Station directly below the building.

Monumental infrastructure  

One40 William is a landmark commercial development in the Perth Central Business District. The contemporary, 19 storey tower and three heritage buildings comprise approximately 43,600 square metres of floor space and accommodate around 2500 workers. Approximately 36,000 square metres is set aside for office space, accommodating a number of different Government agencies. An area of 36,000 square metres is additionally set aside for shared facilities including a reception area, public interface areas, a data centre, meeting rooms and conference facilities. 7,600 square metres of retail, food and entertainment tenancies are open to the public. This mix of land uses is strategically located above the Perth Underground Train Station and provides convenient access to public transport options, establishing a focal point for the City’s transport hub. 

The land use mix is supported by a number of other design features that contribute to an active community.

One40 William
One40 William

Internal design

  • The building design is sustainable and exceeds the standards set in the Government Accommodation policy. In addition to sustainability excellence, the One40 William development has specifically supported workplaces that have access to natural light, working ‘community hubs’, shared open space areas and ability to co-locate working groups.
The land use mix is supported by a number of other design features that contribute to an active community.
The land use mix is supported by a number of other design features that contribute to an active community.

Permeable building design

  • One40 William has a highly accessible ground plan at 42% of the total site area, comprised of integrated pedestrian lanes, courtyards and squares. Some 17% of the public open space is open to the sky.  External open spaces within the tower include landscaped wintergardens, which provide an active ‘external’ space, which can be utilised by office staff.  

Movement networks

  • One40 William has frontages to Wellington Street, William Street and the Murray Street Mall. The building is centrally located to rail, bicycle and bus networks, providing exceptional access for workers and visitors. The significant permeability of the development enables pedestrian flow and movement.
  • All areas of the One40 William development are linked horizontally and vertically, both visually and physically, by laneways, courtyards, elevated walkways and vertical transport systems. General public access is available 24/7 to ground level laneways and squares.


  • Active frontages have facades designed to be protected by fixed horizontal and vertical sunshades ensuring a passive solar response. Safe high quality pedestrian connections link the train stations, Forrest Place, Murray Street Mall, Wellington and William Streets to existing and new buildings.
  • The restoration of the Wellington Precinct buildings and the reinstatement of the Mitchell Building façade will restore these buildings to a recognised heritage standard and positively contribute to a local sense of place. The design of the building preserves the historic building fabric and encourages access to major street frontages and the pedestrian mall.

Project Team

  • Cbus Property
  • Department of Treasury and Finance

Project Cost 

$220 million

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