Kahukura: Is It Christchurch’s Greenest New Building?

A clever, beautiful, $34 million sustainable building deploying innovative building technologies is soon to open in Christchurch at Ara’s central campus on Moorhouse Ave.

Arguably the greenest building in the Canterbury reconstruction programme, Ara Institute of Canterbury’s new, three storey, 6500 square metre architecture and engineering building – “Kahukura”, for 620 students – has been designed (by Jasmax) to use and visually display building and sustainability techniques so that students can learn.

Unusually for a tertiary institute in NZ, Kahukura is made mostly of timber and it is a vast and significant gesture to environmental care. Façade walls are Nelson made cross laminated timber (CLT), with exterior insulation and a German made cladding known as GRC (or Glassfibre Reinforced Concrete). The main structural frame of the building is engineered structural timber called LVL (laminated veneer lumber) from Nelson (rather than steel). Inside, the building also features linings of both engineered plantation pine and sustainably grown New Zealand black -butt eucalyptus.

Jasmax has designed the building so that students can actually see into the building’s construction and learn from it. The building techniques are left on display so they can be discussed - including some steel, exposed concrete, the engineered timber and the building’s services. “The play of light, the scent, fresh air and tactile nature of the materials allow design students a sense of what is possible in design to uplift the human spirit,” says Jasmax Associate and Principal Architect Richard Hayman

As well as using renewable, plantation timber, the large building’s other environmental and conservation issues have been thoughtfully addressed.

On the roof is an array of 400 photovoltaic (solar) panels, expected to generate 40% of the building’s energy load. Through the building’s insulation and other built components, this load has already been reduced to well less than half of that of Ara’s existing facility. This array is monitored via a web service, which graphs energy usage and trends. There is also a solar hot water system.

“The target for this building was the Living Building Challenge ‘net zero energy ready’,” says Richard. “That means our purpose was to move Ara towards needing to purchase no energy for the building. They can add more panels in the future.”

“Kahukura” is a “chiefly cloak”, in te Ao Maori. “So the building is conceived as gently cloaked or wrapped by the cladding and heavy insulation. The façade colour and patterning represents an abstracted feathered cloak. The warm timber lining is also routed on the inside to echo the woven inner flax strands of a Maori cloak,” says Richard.

This story for Kahukura’s design was developed alongside the Ara’s Te Puna Wānaka team and local iwi. “As well as the physical representation of a cloak, the high performing exterior of the building is meant as a practical living metaphor for the protection of those who are inside learning, using it. It confers mana on the students,” says Richard.

The campus in and around the building is undergoing landscaping with locally selected plantings, and the building gathers its own rainwater which is used within the building

“Again, we’ve tried to reduce water usage by 50% relative to the existing facility,” says Richard. “The harvested rainwater is for non-potable usage, such as for toilets.”
Kahukura also sought to ensure fresh air flowed through the structure. “Most spaces have opening windows and natural ventilation,” he says.

Nearly all of the building materials specified are toxicity free, not containing chemicals listed in the Living Building Challenge’s ‘red list’ of toxic products. The laminated timber beams (LVL), for instance, avoid the need for steel beams, which must be painted in a highly toxic intumescent paint as a fire retardant. “Laminated timber will only char in most fires, whereas uncoated steel bends and collapses in high heat fires,” says Richard.

Inside the building are:

- Two Natural light-filled atriums (lit from clerestory windows) and learning spaces.

- Flexible learning spaces, labs.

- A dramatic, wide central staircase. This sits alongside stepped, colourful, seating for informal lectures and meetings.

- Colourful, inviting café area.

- A public exhibition space for student work.

The building will be home to architectural, engineering, quantity surveying and interior design students.

“This building is aspirational for Christchurch. We hope it will set a new benchmark for public buildings in the city,” says Richard. “It makes a significant statement in the education of Cantabrians literally and figuratively, who have said they want the new city to be ‘greener’”.

ENDS

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