Green refit for Aorangi House leads the way

The refit of Wellington's Aorangi House has led the way for other building owners, showing the property sector that retrofitting to new green standards can be viable.

The $8 million refurbishment was a unique collaboration between building owner Prime Property Group, main tenant Beca, and architecture company Studio Pacific.

Engineering consultancy firm Beca, which moved into the building in July 2009, was the overall Large Business winner at the Sustainable 60 awards this week, in part for its role in the refurbishment.

Aorangi House was the first office building in New Zealand retro-fitted to get a 5-star Greenstar accreditation, a voluntary ratings system administered by the New Zealand Green Building Council (NZGBC).

An NZGBC spokesperson said the demand for accreditation from refurbished building owners was definitely increasing.

Chief executive of Prime Property Eyal Aharoni was "very keen" to replicate Aorangi House's success with a building of similar size and age, also on Molesworth Street.

He said the future of building would inevitably head further towards cost effectiveness and energy efficiency.

"I'm getting enquiries all the time from developers, tenants and from other building owners about doing the same for their building."

Victoria University's director of building science Guy Marriage, who was project architect for the retrofitting, said the work done on Aorangi House would lead the way for other commercial buildings using similar design principles.

"My feeling is that that's actually going to become a lot more common in the Wellington market, and probably in the Auckland market as well."

Wellington buildings dating from the 1970s construction boom, like Aorangi House, would all need to be refurbished at some point, he said.

"A lot of them are being deserted by tenants because they're not up to scratch."

Aorangi House itself had been largely unlettable, standing vacant for four years after the previous tenant - the Department of Statistics - moved out in 2005.

"It was even known around the city for being a poor performing building", said Stefan Waldhauser, Beca's manager of Wellington building services.

"We thought we had the capacity to turn that around."

Waldhauser had an advisory role in the refurbishment back in 2008 and has monitored the results since. He said the original focus was to make the office space better for workers, as well as to increase energy efficiency.

The building had "good bones" said Waldhauser, but ventilation and insulation were far from optimal.

Attaining Greenstar accreditation had started out as a secondary objective, but many of the upgrades "naturally went hand in hand" with the NZGBC ratings.

For example, part of the re-fitting included the installation of double-glazed curtain walls, sunshading louvres, a natural ventilation system and cycle and shower facilities for staff.

Beca had plenty of interest since the refurbishment, with Waldhauser guiding various groups through the building and explaining the features to them.

"I've been taking architect's clients, school classes, students - you name it", he said. "I think in general, people left the visit quite inspired".

And another building nearby had also started a similar office extension and refurbishment.

"That's laid the path for them to do something similar, and have the comfort that it's going to work as well", said Waldhauser.