Building NZ's tallest all timber moment-framed structure

University of Canterbury’s four-storey Beatrice Tinsley Building is not only a stylish new learning environment for staff and students, but also the tallest structure in New Zealand to be built with an all timber moment-frame. 

Replacing an outdated, earthquake damaged structure that once stood in its place, the Beatrice Tinsley building, completed in 2019 forms the focal point for the University of Canterbury’s (UC) new science precinct, with connections to the Ernest Rutherford and Biology buildings.

Standing 4 storeys tall and constructed entirely of LVL (laminated veneer lumber) timber (310m³ in total), Beatrice Tinsley is also the tallest moment-framed building in New Zealand to use this material exclusively for its framing structure. Driving this unconventional selection of timber was the design team’s consideration of structural engineering solutions that would limit damage under future seismic events, such as earthquakes which devastated the city of Christchurch in 2011.

Another key driver was the desire to reuse the existing 1960’s concrete basement of the old Von Haast building – both to reduce costs and minimise disruption to the many essential services running through the basement, that service the entire campus.

Being a relatively lightweight structure, timber is ideal as it reduced the gravity and lateral loads applied to existing basement walls, thereby avoiding the need for significant remedial strengthening works. It’s also a less carbon-intensive material and by reusing existing remnants of the previous building, it’s also contributed to lowering UC’s carbon footprint.

Once construction began, LVL columns and beams were installed, supporting stressed skin ‘Potius’ timber floor units. Lateral load resistance was achieved by placing transverse post-tensioned Pres-lam LVL frames in one direction, and concentric LVL cross-bracing in the other direction. 

The final result is a stylish, comfortable and seismically resilient 4-storey structure that was built using the very Pres-Lam LVL system the University of Canterbury pioneered in the 2000’s.