AUCKLAND -- On the corner of Queen Street, Shortland Street and Jean Batten Place lies Auckland's take on the post-Inconvenient Truth high-rise office tower.Symbolic of private business embracing the green building ethos in the mid 2000s, the design of the Deloitte Centre prioritised sustainability alongside traditional commercial concerns of economy, utility, durability and comfort.

Completed in January 2010, the new home for the BNZ and Deloitte is the first high-rise commercial development in the country to be awarded a 5 star rating (NZ Excellence) by the New Zealand Green Building Council under Green Star Office Design.  The building has subsequently been awarded a 5 star rating under the council's €˜'as-built'€™ rating.

At a total height of 120 metres over 25 levels, with a net lettable area of 23,000 square metres, the handsome building sits prominently on Auckland’s skyline. The $145 million project has a special two storey architectural feature which screens the top two plant levels.

Geoff Wicks, Regional Director for Brookfield Multiplex Constructions (NZ) Ltd who handled construction, says that the building is a fantastic design outcome for Auckland. "€œThe Deloitte Centre is a response to the shortage of premium A-grade commercial property within the CBD, redeveloping a previously aged prime Queen Street location with an environmentally friendly office tower and ground level retail."

The high-rise has a unique double-skin façade on the Queen Street elevation that utilises high performance low emissivity glass to help the tower stay warmer in winter and cooler in summer. To balance light transmission and heat gain a 600mm cavity extracts hot air at the top while inlets at the base draw cooler air in, maintaining the internal facade'€™s consistent temperature. The remaining elevations incorporate low emissivity glass into a double glazed curtain wall system manufactured by Thermosash.

Roger Giese of Thermosash says that Bradford Insulation products were used to assure the thermal performance of the curtain walling system in the most cost-effective manner.

"€œBradford Supertel has been incorporated into the spandrel panels of the curtain walling system at each floor beam junction",€ says Mr Giese. "€œSupertel was selected as it not only provides a healthy and comfortable environment but also offers maximum thermal performance at minimal thickness."€

The Supertel was faced with Bradford Thermofoil 730. This tough medium duty foil has high reflective properties that provide additional thermal insulation and reduce temperature variations and condensations internally.  The foil faced glasswool laminate achieved the thermal requirement at minimal thickness reducing the aluminium cost within the façade system.

Mr Wicks says that the Environmental Choice rating of Bradford’s insulation products helped the Deloitte Centre get full 5-star recognition by the NZ Green Building Council.

"We were really appreciative of the dedication shown by Bradford Insulation in assisting us to achieve our goal of a 5 star green rating."

€œBradford operate on a recycled content of up to 82% and carry Environmental Choice certification on a number of their products. "In addition to this,"€ Mr Wicks adds, "€œBradford Supertel increases energy efficiency and minimises greenhouse gas emissions, all of which contribute to a greener building."

Bradford Insulation went so far as to prove its products’ sustainability on behalf of Brookfield Multiplex Constructions (NZ) Ltd, as specialist insulation products are not covered by current Environmental Choice categories.

€œ"Environmental Choice have only one category against which insulation products can be assessed,"€ explains Wendy Robinson, Bradford Insulation'€™s New Zealand Manager. "€œThermosash and Brookfield recognised that Bradford'€™s Supertel foil laminate was the correct product for the application, yet the Environmental Choice category does not easily accommodate specialist insulation products or insulation laminates or composites.

€œBradford worked hard to provide the necessary evidence that although the product could not be assessed under the Environmental Choice category, it was in fact manufactured in the same factory and by the same process as the Bradford products which do have the official green tick. The same type of glass and the same binder is used and although quantity of glass may vary to achieve the necessary density, Bradford is aiming for the same glass chemistry and finished product quality as its '€˜green ticked'€™ range.

For over 70 years Bradford have been creating environmentally sustainable products to help improve the comfort and energy efficiency of commercial and residential buildings.

For more information view Bradford Insulation'€™s technical manual in the eboss library or visit their website.