The Ironbank building in Auckland’s Karangahape Road has had its construction certified by the New Zealand Green Building Council with a 5 Green Star – Office Built rating.

The rating represents ‘New Zealand excellence’ in sustainable construction.

An Office Built certification assesses the completed construction of the project. Ironbank has now verified that the green building strategies designed into the building were incorporated into the final construction, says NZGBC chief executive Jane Henley.

“Ironbank’s certification validates that the promise of the design has been realised in the construction. It brings the green design features from the theoretical to the practical,” says Ms Henley.

Ironbank is the second project in New Zealand to achieve a Green Star – Office Built rating, and the first to achieve a 5 Star rating.

The Green Star system assesses the environmental attributes of a building at three phases: Design, Built and then Performance (to be developed this year).

Ironbank is unique in that it had not already achieved a Green Star – Office Design rating, which is normally achieved prior to construction. Samson’s Marco Creemers says a few “well educated assumptions” were needed.

He says it was in the details that they had to make fundamental changes, and the challenge posed in reaching a 5 Green Star – Built rating was probably greatest for the contractor, Macrennie Construction.

Demonstrating green design
The project team had to change the way they managed the construction, particularly relating to the management of waste on site, and handling the associated paper work demonstrating actual implementation of green design initiates.

Some of the green features of Ironbank include:

• 100 per cent outdoor air ensured via an effective, flexible, natural ventilation strategy with night purging;
• 25 per cent of car parks are designated for small cars;
• cycle racks are provided;
• stormwater collected and distributed to low flush toilets and landscape irrigation system;
• solar water heating;
• efficient lighting system;
• an automatic car stacking system;
• and 94.5 per cent construction waste was recycled.

 “We all took our chances, to some degree, but it paid off with the Ironbank’s Green Star – Office Built certification in New Zealand.”

Samson Corporation recognised long ago that environmental performance would become an important point of difference – good quality spaces that are pleasant to be in, while reducing operating costs, says Marco.

Ironbank was designed by RTA Studio and reflects Samson’s goal of “architectural statements that pass the test of time” and is proof that green buildings can be attractive too, he says.

“Green Star ratings are a natural progression for us. We’ve always used green thinking to make a difference for tenants and now there’s something to quantify this difference.”

Samson Corporation say they have invested between seven and 10 percent more than they would have in a ‘normal’ building of the same scale, with a maximum pay back period for the additional expenditure of four to seven years.  

Words of advice
So what advice does Marco have for those who seek a Green Star – Office Built rating? 

“Green buildings are common sense and the way of the future. If you're building it’s worth doing properly. It's a long-term asset you’re creating.”

“Do it right before legislation and the market force you to. The major consideration in terms of price is the cost of time, but with good planning at the front end you can minimise this effect and, although it costs more upfront, you and your tenants will reap benefits over the longer term, he says.

Samson Corporation has also achieved a 6 Green Star – Office Design rating for their planned 4,600 square metre office space, Geyser, in Parnell.

The Ironbank retail office building was designed by RTA Studio for Sampson Corporation.