Entrant:
Foster Construction Group
Category:
13. Hybrid Building Award
Overview
BNZ Theatre
BNZ Theatre is a state-of-the-art performing arts venue created to restore the cultural heart of the Waikato following the closure of Founders Theatre.
Located within a constrained riverfront site and integrated with the Category 2 listed Hamilton Hotel façade, the project combines an auditorium with hospitality spaces and a multi-level public foyer.
Designed as an IL3 public building, it required the robustness of steel and concrete primary structure, with carefully introduced timber delivering enhanced performance, buildability, and environmental outcomes.
Purposeful integration of materials:
Steel and concrete provide the long-span capacity, seismic resilience and durability required of a major civic venue. Cross laminated timber (CLT), manufactured from engineered pine, was strategically introduced in secondary structural elements including the auditorium roof, bleachers, catwalks, and blade walls.
Acting as a structural diaphragm, the CLT roof reduced the need for additional steel bracing and eliminated a suspended triple-layer acoustic ceiling.
In the bleachers, prefabricated CLT panels achieved complex curved geometry that would have been inefficient and heavy if fabricated in the originally specified precast concrete.
In the blade walls, CLT provided a lightweight structural substrate for stone cladding, also providing flexibility for fixing locations.
The successful outcome relied on the complementary strengths of the materials used: steel, concrete and timber.
Engineering challenges resolved:
The project navigated significant redesign pressures, heritage integration and a constrained construction programme.
Notably, 335m³ CLT was used in the construction of this building. The lighter weight CLT reduced imposed loads on the primary steel frame and foundations, optimising overall structural demand. Off-site prefabrication improved sequencing and reduced crane time, taking key elements off the critical path. CLT’s diaphragm action simplified roof construction and reduced temporary works, improving safety in the five-storey auditorium void.
Acoustically, the mass and layered composition of CLT enhanced mid and high frequency reflectivity while preserving low frequency resonance, reducing reliance on secondary linings.
Fire performance was addressed through inherent charring resistance, selective overcladding and intumescent coatings, while an extensive moisture management regime safeguarded long-term durability.
BIM coordination ensured precise interfaces between steel, concrete and timber systems.
Expression and architectural value:
The use of timber is both structural and experiential. CLT within the sculptural blade walls, the roof, bleachers and catwalks establishes material continuity within the building. CLT also proved more adaptable to the curved seating geometry.
A bespoke timber acoustic halo further integrates structure and performance technology.
Within the foyer, cantilevered timber staircases gently juxtapose steel framing and concrete slabs.
Timber features, like the heritage oak Hamilton Hotel staircase and timber portals, reclaimed rimu flooring, walnut, and beech joinery create a dialogue between detailed craftsmanship and mass timber engineering.
Value added:
Timber delivered measurable embodied carbon reductions and programme efficiencies, with labour savings and simplified fixing processes contributing to cost certainty.
Aesthetically, timber tempers the scale of the civic volume, adding tactility and acoustic refinement.
The BNZ Theatre exemplifies hybrid construction: steel for span and resilience, concrete for permanence, and timber for acoustic performance, buildability, carbon reduction and cultural expression.