Project Overview
The Beca Stairs project is part of the Momentum development, featuring multi-level internal stair systems that act as both functional circulation elements and architectural features. The project demonstrates how engineered timber can be used to deliver highly detailed interior structures that combine structural performance with refined architectural expression.
The stair systems required careful engineering to accommodate complex stepped geometries across multiple levels, while maintaining clean lines and a high-quality exposed timber finish.
Red Stag TimberLab's Involvement
Red Stag TimberLab (RSTL) supplied the engineered timber structural components, including the primary Glulam spine beams and Cross Laminated Timber (CLT) stair treads and landings. These elements form the structural backbone of the stair systems and were manufactured to tight tolerances to ensure accuracy and buildability.
A defining feature of the project is the scale and curved geometric complexity of the Glulam spine beams. Manufactured from large-section GL10 members, approximately 675 mm wide and up to 740 mm deep. The spines act as the primary load-bearing elements supporting stair flights and intermediate landings.
RSTL worked closely with the project team to digitally model the intricate stepped geometry of the stair structure. This enabled precise coordination of connections, interfaces, and alignment across multiple levels, ensuring the design intent was accurately translated into manufactured components.
Prefabrication and Installation
RSTL fabricated the Glulam spine beams with a high level of precision, incorporating recessed cut-outs and pre-engineered connection details to accommodate stair treads, landings, and fixings. The complexity of the geometry required careful CNC machining to achieve the required accuracy across both stepped and angled sections.
The components were delivered to site as precisely machined elements, reducing the need for on-site modification and supporting efficient installation. This prefabrication approach improved build speed, reduced installation risk, and maintained clean, exposed timber surfaces.
CLT stair treads and landings were detailed to align accurately with the Glulam spine structure, forming a cohesive and visually refined stair assembly.
Results
The Beca Stairs project delivers a highly detailed and structurally efficient stair system that highlights the capabilities of engineered timber in complex interior applications.
The use of large-scale Glulam spine beams combined with precise prefabrication enabled the successful execution of a challenging multi-level geometry. The result is a robust and visually striking feature that demonstrates how mass timber can achieve both technical performance and architectural quality, while also contributing to a more sustainable construction approach.
Project Credits
Architect: Warren and Mahoney Architects
Engineer: Beca
Builder: Hawkins Construction
Product: Glulam stair spines, CLT stair treads
Contact the Red Stag TimberLab team to discuss how you can include mass timber in your upcoming project.
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Email: info@redstag.co.nz
Phone: 09 253 9349
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