Green light

by Listener Archive / 29 May, 2010
Far more could be done to make commercial building truly sustainable.

New Zealand's housing may be in a parlous state, as noted in our cover story two weeks ago, but commercial building has taken impressive strides in the past few years as "green" office buildings started to gain real cachet. The country now boasts two six-star buildings, as rated by the New Zealand Green Building Council, plus a clutch of five- and four-star office and industrial developments.

Auckland architect Justin Evatt says the council has "helped create a market for the green building. By having tangible star ratings, they've created the market and the capital follows."

Evatt works at Jasmax, whose entire business is now run through the oversight of colleague Jerome Partington, the firm's sustainability manager. But although Evatt applauds what the green-star system has done to lift the game in New Zealand (Jasmax boasts several starred buildings in its portfolio), both he and Partington say far more could be done to make commercial building truly sustainable.

And what they mean by sustainable is far-reaching stuff: much more than simply saving on your power bill. "That gift that occurred somehow for us to be on this planet - we're going to stuff it up," says Evatt. "We've got to see it as being a gift. And if we don't look after the systems that provide for us, then we're stuffed."

Educating their clients is a key first step - one of Partington's favourite graphics is a graph showing resource use shooting up and available resources heading down. Somewhere in the gap before those two arrows meet is where we need to be, he says.

And that raises the great question mark over green buildings: are they sustainable? Says Partington, "There is some evidence from the US that green buildings could consume more energy than commercial buildings. Green buildings tend to be prestigious buildings, so they tend to be glass buildings on all four sides. It's very hard to get an energy-efficient glass box. It's a greenhouse, basically. So yes, there's a lot of technology we can use to improve it, but if your ­initial decision is to produce a glass tower, then you're going to have a real problem trying to achieve a sustainable building basically."

Evatt adds: "That's where your aesthetic drivers aren't aligned with your sustain­able drivers. You can tick all the boxes like having bike racks and showers for staff and you can get a whole lot of points for things, but fundamentally you've made an inefficient building to start with."

In fact, what might be a green, energy-efficient building now could be undone in a few decades when temperatures rise another couple of degrees. "If we've designed a building that's comfortable in the current ambient air temperatures," Partington says, "when those temperatures go up in the city, you're not going to be able to cool your building and suddenly what you spent your money on 20 years before is redundant. The cost of energy will be so great to cool the building that you've blown it. Whereas if we design the highest-performing most energy-efficient building now, that will be able to carry itself through a degree of warming. And that's passive building, more shading, smaller windows, getting rid of the mechanical plant and getting natural ventilation in to give you radiant comfort."

Although green building has captured the public's attention, Partington thinks we're still "dealing in eco-creep", addressing issues as they arise, rather than taking the kind of long view that considers how a building will perform in 10, 20 or more years' time.

So what would be truly sustainable? "Buildings have to earn the right to occupy the space that they do on the land," Partington concludes. "If you had buildings that produced more energy than they used, collected all the water that they needed from the site, and when they emitted it from the building it was cleaner than when they took it in - likewise the air - and there's also a place to help increase biodiversity ... if you can start to conceptualise buildings like that, that's the ideal state. Then you start to get sustainable buildings."

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