Overview
Entrant:
Jasmax
Category:
12. Mid-Rise Building Design Award (over 3 levels)
Photographed by:
Jasmax
Key team members:
Architect (base building, interiors, landscape): Jasmax
Engineer (structural, services): Beca
Engineer (façade): BEG
Building/contractor: Naylor Love
Project Manager: RDT
Acoustics: Marshall Day
Quantity Surveyor: BBD
Tukutuku is a four-storey learning facility forming the social and academic heart of AUT University's North Campus in Auckland.
Delivered as part of a campus revitalisation, the project combines the adaptive reuse of the existing 50-year-old AF building with a new mass timber structure (AZ building), including a four-storey atrium.
The client’s challenge to the design team was to ensure that the choice of timber did not result in a building that cost more than a ‘business as usual’ steel framed structure with concrete floors. The soil conditions were poor, raising questions about foundation depth. Through close collaboration with the quantity surveyor, the team discovered that steel and concrete could achieve three storeys with shallow footings; however, timber’s lightweight properties enabled an additional storey on similar foundations, offsetting any cost premium associated with the mass timber structure, by delivering additional floor area.
One of Australasia's largest post-tensioned engineered timber structures, Tukutuku’s structural system employs three-bay LVL Pres-Lam frames that brace the building transversely, creating flexible 9m span teaching spaces. Lightweight prefabricated Potius floor panels span 5.6m between the frames. LVL timber diagonals provide longitudinal bracing. Each frame was fabricated from precision-engineered timber components supplied by RSTL, which were assembled flat on-site then craned into place as complete three-storey elements, accelerating construction and ensuring quality control.
Structural efficiency is about recognising that materials possess complementary strengths and weaknesses, informing how and where they are best used. Tukutuku’s timber columns rest on precast concrete bases where they transition to the building exterior, benefitting from concrete’s inherent durability. Steel is great in tension. Timber works best when loaded in compression and parallel to the grain. The Pres-Lam frames use post-tensioned steel within voids in primary beams, which are preloaded in compression.
Tukutuku shows how timber can economically and elegantly be used for multi-storey construction in a seismic region like New Zealand. The bracing system is well distributed, reducing the demands on the diaphragm and lateral load resisting systems. Load paths are separated where possible to simplify joints and permit repetition and standardisation.
The structural timber remains visually exposed throughout, creating warm spaces that showcase New Zealand innovation to students. The post-tensioned LVL frames, Potius floor systems, and diagonal bracing elements are celebrated rather than concealed – expressing the structural logic and materiality honestly while providing an attractive finish. The timber frame is structurally oversized to allow charring, retaining structural integrity in the event of fire.
The exposed timber structure creates biophilic environments fostering connection to nature, positively impacting occupant wellbeing. In Tukutuku’s first year of operation, student satisfaction on the North Campus increased 14%, validating the project’s effectiveness in contributing to student engagement and campus vitality. The four-storey atrium showcases the full height of the structure, expressing timber’s capacity for spatial generosity in multi-storey contexts, presenting an elegant, economical alternative to steel and concrete.
Timber species/applications:
- Structure: LVL from sustainably grown radiata pine (Northland)
- Floors: Potius Double-T system, radiata pine (Nelson)
- Interior finishes: Sustainably certified timber panelling selected using EPDs