World’s Tallest Hybrid Timber Tower Tops Out In Sydney
Atlassian Central has reached its full height in Sydney, making it the world’s tallest hybrid timber tower. The completion of the final structural level, known as topping out, marks a major milestone for the 39-storey building, which rises more than 180 metres above the city.
Designed by architecture practices BVN and SHoP, the tower is approximately 100 metres taller than the previous record holder: the 25-storey Ascent tower in Milwaukee, United States. It demonstrates how mass timber can form part of a high-rise structural system while meeting strict safety and performance requirements.
A Hybrid Material Structure
Atlassian Central combines mass timber with steel and concrete. Timber reduces the building’s overall weight and carbon impact, while the steel and concrete elements provide the strength and stability required at this scale.
According to BVN, the hybrid mass timber approach also supports prefabrication, dry construction and a lighter, faster vertical building process. However, combining different structural materials within a 39-storey tower required precise planning and complex construction sequencing.
Australian contractor Built is delivering the project in a joint venture with Obayashi Corporation. Digital engineering, advanced modelling and virtual construction allowed the team to plan the assembly of the timber, steel and concrete components before work began on site.
Reducing Embodied Carbon
The project targets a 50% reduction in upfront embodied carbon across its structure compared with a conventional premium commercial office tower. It also aims to improve operational energy efficiency by 50% compared with a conventional 5 Star NABERS base building.
A four-storey ‘habitat’ structure forms an important part of the workplace concept. It combines natural materials, daylight, landscaping and natural ventilation with spaces for working and collaboration. This biophilic approach seeks to connect occupants with nature, the surrounding city and one another.
The building will also use digital systems to sense and respond to changing conditions in real time. These technologies aim to support energy performance and adapt the workplace to future patterns of use.
Construction Continues
With the structural frame complete, work will continue on the façade and central building services. Practical completion is scheduled for the end of 2026.
Atlassian Central is co-owned by technology company Atlassian and property group Dexus. Dexus is developing the project, while Built and Obayashi Corporation are responsible for its delivery. The completed structure provides a large-scale example of how mass timber, digital engineering and hybrid construction could reduce the environmental impact of future high-rise buildings.
Source & photos: BVN / Dexus