A landmark for Sydney’s business district

The design for 100 Mount Street is inspired by Sydney’s rich architectural landscape and shaped by SOM’s legacy of innovation in architecture and structural engineering. The 35-story office tower offers panoramic views of Sydney Harbor, the Sydney Opera House, and Sydney Harbor Bridge, while creating welcoming new public spaces and amenities at its base.

At ground level, the building’s offset core allows for a series of highly flexible, open-concept spaces, including a commercial lobby, café, and restaurant. These areas are sheltered from the elements by a nine-meter-tall glass wall. From the landscaped public plaza, with cascading steps and inclined pathways, visitors can access new shops and cafes at the lower street level, while a pedestrian route bisects the site to connect the building to nearby public transit.

The tower’s interiors are designed to maximize daylight and open space, with 6-meter column-free zones to the north and south. Together, the offset core and high-performance closed cavity facade allow for automatic daylight control and reduce glare, while maintaining maximum transparency.

Engineered for efficiency and elegance

The tower’s highly efficient structural system and exposed mega-bracing are designed to manage the building’s torsional response, while minimizing the size, cost, and carbon footprint of the bracing system. This design helped to reduce steel quantities by 10 percent for lateral loads, while also lessening the impact of vertical creep and shrinkage stresses. SOM’s structural engineers developed the innovative cross-braced exoskeleton structure by using topology optimization algorithms and classic structural analysis.

The tower features highly transparent glazing, subtly articulated by exposed structural elements. The elegantly proportioned bracing on the east facade gives the tower a distinctive identity on the North Sydney skyline.

Taking sustainability to greater heights

100 Mount Street reflects a commitment to sustainability that exceeds typical office buildings; it considers total life-cycle impact, in addition to targeting environmental ratings in design and operation. A range of strategies and systems, including chilled beam systems and motorized Venetian blinds, reduce the building’s environmental footprint. The office layout also prioritizes natural light, allowing for open and light-filled spaces. The project is targeting 5-star ratings on the Australian Green Star and National Australian Built Environment Rating Systems.