Christchurch will soon be home to two new commercial buildings built of Expan, a post-tensioned laminated veneer lumber (LVL) building system that makes lightweight, seismically safe multi-storey timber buildings commercially viable.

Developed through The Structural Timber Innovation Company (STIC) – a New Zealand-based research consortium – Expan buildings can be constructed quickly, at an equivalent cost to steel or concrete. Expan’s unique post-tensioned technology combined with the flexibility of timber also enables unique superior seismic capabilities. Dr Robert Finch, Expan’s CEO, says the Christchurch timber buildings will be hugely significant examples of cutting-edge seismic design, and damage avoidance technology.

“Commercial property owners – and insurers – are now demanding buildings that are not only safe in a major event, but can be rapidly reoccupied afterwards and therefore minimise business interruption. Seismic capabilities are certainly top of mind for property owners in New Zealand now.” With a national focus on building safety in the wake of the Canterbury earthquakes, Dr Finch has seen a steady stream of interest in Expan’s seismic capabilities from around the country.

“We’ve seeing a number of queries from Wellington, and throughout New Zealand, as building owners take a fresh look at the seismic risk associated with buildings. We’re also taking calls from people contemplating new builds who are looking to construct something that will offer good resistance from seismic activity.” There are already seven Expan buildings in New Zealand, including the award-winning Nelson Marlborough Institute of Technology (NMIT)’s new Arts and Media Building, and the Carterton Events Centre in Carterton.

“People have always loved timber,” says Dr Finch. “They love that it’s a natural product, it’s sustainable, with a warmth to it you don’t get with other materials. Thanks to LVL technology, it can now hold its own against steel and concrete as a viable alternative for commercial buildings. LVL is a highly consistent, high strength engineered timber product. Engineers and architects are now realising timber is a real option, it’s not just a nice idea anymore.”

A new office building proposed for 134 Victoria Street will be constructed of a highly resilient three level Expan LVL timber frame – the first Expan office building to be constructed in central Christchurch. It is a post tensioned timber frame relying on cables within the beams and steel energy dissipator clamps at the junctions to strengthen and brace the building. It is clad in glass on two sides to display on the outside the warmth of the timber interior along with the quake resistant dissipators and post tensioned cable ends.

The use of a LVL timber frame structure without shear walls will be a world first example of this particular version of the Expan technology. It is a damage avoidance system which can resist large earthquakes successfully without incurring significant and costly damage, while keeping its inhabitants safe. Using locally grown Radiata pine for the structure also creates a highly sustainable building and an attractive, warm, pleasant interior.

Jasper van der Lingen, the architect behind the new building, says he sees a big future in wooden building technology – and a definitive reason why New Zealanders are so keen to build in wood.

“I think this technology is very special to New Zealand; after all , we are a timber country. It’s fantastic to be able to use a local, sustainable resource, and locally developed technology, to design a unique looking, long-span commercial building that’s not been possible here before.”