Q&A with Tzannes: Daramu House and International House Sydney / The Future of Mass Timber Construction
As cities grapple with the environmental cost of construction, Daramu House and International House Sydney presents a compelling case for mass timber as a viable alternative to conventional materials. Designed by Tzannes and located in Barangaroo, the seven-storey office buildings builds demonstrate refining prefabrication techniques, reducing embodied carbon, and prioritising occupant well-being. Beyond its structural innovation, Daramu House and International House Sydney integrates biophilic principles, urban connectivity, and advanced sustainability strategies to redefine what a commercial workplace can be. In this conversation with Tony Lam of Tzannes, we explore the project’s impact, from material selection to long-term adaptability, and consider what it signals for the future of urban development.
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photography by The Guthrie Project and Brett Boardman, published with bowerbird
How has International House Sydney influenced the perception of mass timber as a viable alternative to conventional materials?
International House Sydney (IHS) set a precedent for commercial mass timber construction in Australia, proving that engineered timber could challenge conventional materials both structurally and aesthetically. By demonstrating the efficiency of prefabrication, reduced construction waste, and significant carbon savings, IHS shifted industry perspectives on mass timber’s commercial viability. Daramu House builds upon this success, further embedding mass timber into Sydney’s urban fabric and reinforcing its potential to redefine sustainable commercial architecture.
How do Daramu House and IHS set a precedent for sustainable commercial developments in dense urban precincts?
Both buildings exemplify the potential of mass timber to achieve high environmental performance while maintaining commercial appeal. Daramu House achieves a 6 Star Green Star rating, exceeds the 5 Star NABERS benchmark by 30%, and targets WELL v2 Core Certification—a testament to its holistic approach to sustainability. Through thoughtful material selection, prefabrication efficiencies, passive design principles, and renewable energy integration, these projects demonstrate a scalable model for carbon-conscious urban development.
What were the key considerations in material selection, and how did prefabrication enhance the construction process?
Material selection focused on minimising embodied carbon while prioritising efficiency and adaptability. Locally sourced recycled hardwoods reinforce a connection to place, while engineered timber elements—Cross Laminated Timber (CLT), Glulam, and Laminated Veneer Lumber (LVL)—ensure structural integrity and design flexibility. Prefabrication played a critical role in reducing construction waste, optimising material use, and accelerating the build time, enabling a 97% diversion of on-site construction waste from landfill.
How does the use of mass timber improve the well-being of occupants compared to conventional office environments?
Timber’s biophilic qualities foster a warm, inviting atmosphere that enhances occupant well-being. Studies indicate that exposure to natural materials like timber can reduce stress, lower heart rates, and improve cognitive function. At Daramu House, the omission of wall and ceiling linings allows the raw beauty of timber to be fully experienced, while abundant natural light and fresh air circulation further contribute to a healthier and more productive workspace.
How do these buildings accommodate evolving tenant needs while ensuring longevity and material reuse?
The structural grid of 9 x 9 metres maximises spatial efficiency, minimising internal columns and enhancing layout adaptability. Additionally, the prefabricated timber modules can be disassembled and repurposed at the end of the building’s life, supporting a circular economy approach. Features like modular access floors and demountable partitions ensure that the building can evolve alongside tenant requirements while minimising future material waste.
How do the public spaces and urban design elements contribute to Barangaroo’s identity?
Daramu House reinforces Barangaroo’s urban narrative by prioritising pedestrian connectivity and public engagement. Its timber colonnade, activated ground plane, and carefully scaled lower levels enhance the precinct’s human scale. The integration of public art—such as Nicole Larkin’s cross-laminated timber bar relief sculpture in the lobby—celebrates the site’s layered histories, while landscaped green roofs contribute to urban biodiversity and mitigate the heat island effect.
How do the building’s mechanical systems interact with the broader sustainability goals of the precinct?
Barangaroo operates as a carbon-neutral precinct, and Daramu House plays a vital role in supporting this ambition. Its harbour heat rejection system passively cools the building by drawing upon seawater, eliminating reliance on conventional energy-intensive cooling methods. Coupled with a 143 kW rooftop solar PV array and passive solar shading, these strategies significantly reduce operational carbon and align with Barangaroo’s commitment to environmental leadership.
What lessons from International House Sydney and Daramu House can be applied to future urban developments worldwide?
These projects highlight the economic and environmental feasibility of mass timber at a commercial scale. Key takeaways include the role of prefabrication in reducing waste, the importance of integrating renewable energy and passive design, and the broader urban benefits of biophilic materials. As cities worldwide seek to reduce their carbon footprint, the precedent set by Daramu House and IHS demonstrates that aesthetic excellence, commercial viability, and sustainability can coexist in the built environment.
