Preservation of life has always been the main aim of the New Zealand Building Code as it relates to seismic requirements. But a new seismic structural technology is also addressing the life of the building itself.
The recently completed Young Hunter House building, formerly the Merritt Building, in Christchurch, is believed to be the first speculative office development to feature a self-centring LVL timber PRESSS (Precast Seismic Structural System) technology performance-based structure.
Architect Jasper van der Lingen of Sheppard & Rout Architects and engineering consultant Jade Kirk of Kirk Roberts Consulting Engineers worked closely with a development team at the University of Canterbury, which has pioneered the technology.
"At this stage, only a few buildings have been constructed using the system," says van der Lingen. "But the building owner Tony Merritt suggested we explore this new earthquake-resistant timber technology there was a real synergy in that we both wanted to do this. In reality, the disruption caused by earthquakes can be immense and the idea of reparable buildings that utilise damage avoidance technology holds a lot of appeal.
"Traditionally, Christchurch buildings have featured stone, concrete and masonry this is a city that is accustomed to big, heavy buildings that look as though they are going to last forever. But following the earthquakes, that kind of architecture does not seem nearly as appropriate. Instead, we are looking at lightweight, flexible buildings that move with tremors to absorb their energy."
The new building is consequently framed with massive LVL (laminated veneer lumber) beams and columns, with post-tensioned steel tendons running through the beams. Using LVL ensured the beams could be engineered to be longer, thicker and stronger than natural timber.
"Right from the start we decided that we would make a real architectural feature of the technology," says van der Lingen. "All the beams, columns, and frame joints are exposed. Matisse, the retail tenant on the ground floor, took this one step further, exposing all the services. Throughout the building the wood imparts a warm glow that is very inviting."
The design team continued the exposed wood theme in the main lobby, creating a plywood staircase for the main circulation area.