Canterbury University vice chancellor Rod Carr says while it's easy to look at what fell down, Christchurch is still the second largest urban centre in New Zealand, and it remains home to more than 300,000 people.

Fifty years ago the university abandoned what is now the Old Arts Centre in the central city and shifted out to three farms at Ilam.

Carr praises their foresight and says not only has the campus weathered the quakes well - only 14 of the 240 buildings are still out of bounds and only a handful have been demolished - but it is an indication of what the central city could be like in another 50 years.

"If you ask what a city in a garden feels like, it's like walking round here - low rise buildings, mounded land, riverscapes."

The university is using the upheaval to improve where it can, despite the reluctance of its insurers to make things better than they were.

When it found the aftershocks were snapping off pins in the 40-year-old steel windows in the library, the insurer proposed to surround the 11-storey tower with scaffolding, check all 800 windows, and replace only those which were failing with aluminium-framed panes.

"It seemed dumb to replace some and not all, and the windows would only be singled glazed because that is what we had," Carr says.

Eventually the insurer agreed to pay over what it would have paid, and the university is paying extra for double glazing.

"We did a business case and found the pay-back period was 12 years because of savings in heating, so we were able to do it," he says.

"That is a greening of this building that we would probably not otherwise have been able to do."

Carr says greening will occur, and not just in the university.

"I don't think there is any doubt that as the city rebuilds, the choices that will be made, the technologies that are available, the relative cost of all of this stuff will push us in a direction of more sustainable, more eco-friendly structures."