Sustainability key to future housing

00:42, Mar 21 2013
David Hobstetter
DAVID HOBSTETTER: "I think there's a lot of knee-jerk reaction about unitary plans, about everyone being forced to live in a ridiculously dense environment. It doesn't have to be that way."

Kiwis concerned about high-density housing need to think about the consequences, says visiting American architect David Hobstetter.

Noting the debate about Auckland's unitary plan, he says New Zealanders may want their house and patch of land but "the other side is, we need to become more sustainable, more resilient in order to survive global warming and have a resilient economy".

When his hometown of San Francisco reviewed its downtown plan, it looked to Vancouver where higher density housing was light and had good access to amenities. It did not feel like a concrete jungle.

"I think there's a lot of knee-jerk reaction about unitary plans, about everyone being forced to live in a ridiculously dense environment. It doesn't have to be that way."

A keynote speaker at the Green Property Summit in Auckland yesterday, Hobstetter was the principal architect in charge of 525 Golden Gate, the award-winning headquarters of San Francisco's Public Utilities Commission.

Arguably the US' greenest building, it aims to have half the carbon footprint of a similarly sized building, while still fitting in with the historic precinct it is situated in.


The building uses wind and solar power, recycles its human waste and grey water for flushing toilets, and is designed to be operational even after a "good shake".

It is ultimately expected to use a third less energy and 60 per cent less water than its conventional counterparts.

Hobstetter said earthquakes were a daily occurrence in San Francisco so they were at the forefront of architects' minds.

But his clients at 525 Golden Gate also saw seismic performance as being intertwined with sustainability.

"The notion that you design a green building and not make it resilient to an earthquake doesn't make any sense, because when you do a building there's a huge amount of embedded carbon in that building that you've invested.

"So you don't want to design the building so that when the first big earthquake comes around, the building is destroyed."

Hobstetter's design turned away from steel and used concrete, which turned out to be a greener and cheaper solution.

Its concrete slab is used as a thermal sink to chill its airflow at night, avoiding the need for conventional air conditioning.

Concrete walls have been left exposed for some of the interior, reducing the amount of fit-out materials.

And with the help of some suspension bridge-like technology, the 13-storey building is designed to move during an earthquake.

Whether 525 Golden Gate is the greenest building in the States is difficult to say, although Hobstetter says that was the target.

"Once you start talking about this, you go down this road of what is green. We set our own definition to meet that and it was tied to not just energy, it was tied to water use, it was tied to the quality of the workplace and the productivity of the workforce within the building. So it was a multi-faceted definition."

In any case, 525 Golden Gate had achieved its aim of setting an example in the city where people were "very committed to sustainability".

New Zealand also ranked highly for sustainability, fifth out of 110 countries, Hobstetter noted.

"You've got great natural resources here that you utilise to produce your energy. Your big problem is the oil consumption ... and that's part of the discussion you need to have with [Auckland's] unitary plan."

The upshot of his message was that New Zealand needed to design buildings that fully recognised its changing environment.

"Like San Francisco, we come from remarkably similar natural environments. We're both in the 'ring of fire' and the ring of fire has created these magnificent physical settings that we have - the mountains, the water and all. And we should take inspiration from that in the buildings we create... and understand their power.

"If we don't pay attention, they will destroy us, either quickly in a major earthquake or more slowly as we boil away in global warming."