Green shoots for top builds

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Distinctive roof gardens are a growing trend on classy Queenstown construction projects. 

The newly-opened Hilton Queenstown hotel has four roof gardens, the space-age $10 million Jagged Edge super-home has two, and two new mansions reportedly have a roof garden each. 

All eight roof gardens have been installed by Auckland-based Natural Habitats, whose director Graham Cleary says there will be more to come in the Wakatipu. 

“We’re surprised at the number of installations we’ve already done,” Cleary says. 

Cleary puts the growing green-roof trend down to the number of very expensive mansions now going up – some being developed by expatriate Americans who use US landscape designers – together with “the preciousness of the Central Otago landscape”. 

“People are trying to blend their homes more and more into the landscape,” Cleary says. 

Natural Habitats has four full-timers and up to 14 part-timers staffing its local operation. 

Arrowtowner Mark Aston is the firm’s Central Otago area manager. With a former business partner, Aston installed the Wakatipu’s first ‘green roof’ on an Arthurs Point home seven years ago. 

The four Hilton roofs comprise two smaller grassed gardens totalling 20 square metres, a medium-size roof of 80sq m carpeted in red ground-cover plants and a giant-size 220sq m garden planted in a mixture of meadow grass and poppies. 

Jagged Edge has a snow-tussock roof garden atop its newly-completed guesthouse, plus a range of native shrubs in soil up to 600mm deep on top of the garage of the main house. 

Aston makes the construction of a roof garden sound quite technical. 

“You’ve got to put down drainage matting, filter cloth on top, then a depth of planting medium on top of that [and] also polystyrene for insulation,” he says. 

“We generally create a [specific] blend for each roof because each roof has a different weight-load capacity,” Aston adds. 

Natural Habitats maintains its roof gardens for 12 months to ensure they grow and develop as intended. 

Cleary says the impact of a roof garden is “more than visual”, pointing out other benefits such as increased insulation, noise dampening, energy and heat savings, and cleaner air. 

Roof gardens start at about $150 per square metre, he says. 

Then there are ‘wall gardens’, Cleary explains. 

The first wall garden in Queenstown-Lakes will be a 7.5 metre high version going in early next year in Wanaka. 

At about $2000 per square metre, wall gardens are far more expensive than roof gardens because plants have to be grown off-site for six months first, Aston says. 

However, “the result is stunning”, Cleary says.