what lies beneath

Building within New Zealand's active geothermal environment is far from simple. In excavating the site for the Rotorua Energy Events Centre, the construction team discovered a cold water spring, a hot spring with temperatures of around 60ËC and hydrogen sulphide levels well in excess of safe working levels.

Mainzeal Construction's project manager for the Rotorua Energy Events Centre, Peter Donnelly, says the risk of gas escaping was high.

"A gas-proof membrane had to be placed across the entire site, to prevent gas leakage into the building," he says.

Unsuitable foundations meant that 70% of the building platform had to be excavated to a depth of two metres below floor level and filled with compacted metal. One side of the building required 190 piles to be driven into the ground before any concrete footings could be poured.

There are several different venues within the building, including the Southern Trust Sportsdrome, Bay Trust Forum, Unison Arena, Grand Hall and several breakout rooms. With more than 8500m­­2 of floor space, the centre can hold 500 exhibition booths or host a banquet for 3000 or a rock concert for 6000.

The exterior features horizontal silver louvres, which form a curve along the side of the structure and prevent excessive solar heat gain.

In the Grand Hall, one wall is devoted to a display on the history of Rotorua. A pattern frosted on the glazed walls of the entrance depicts Rotorua's lake and island. The doors to the forum are carved with an intricate koru design. A tall, tree-like fibreglass pou in the Grand Hall is back lit with fluorescent tubes.

Both the forum and the arena have suspended ceilings made up of acoustic tiles. The flooring is the International Sports Surfaces system, which has a maple finish. There are two banks of seats at each end of the arena that concertina back into a small unit when not in use.

Donnelly says weekly meetings were necessary to co-ordinate the 16 different trades working on site. Work was completed by dividing the 74m long and 45m wide arena into bays. The various trades then worked sequentially down the arena, on a birdcage scaffold.

For details, contact Peter Donnelly, Mainzeal Property and Construction Ltd, Cessna Place, Mount Maunganui, phone (07) 574 9285, fax (07) 574 9213.

Story by: Trendsideas