SUSTAINABILITY AND THE ROLE OF NATURAL VENTILATION FOR HIGH RISE BUILDINGS IN

NEW ZEALAND.

by Dr Regan Potangaroa

presented by Dr Bin Su

School of Architecture and Landscape Architecture (ScALA) Unitec, Auckland, New Zealand.

Our predicament?

• “…it is sometimes said of those who try to persuade man of his environmental predicament that they paint a picture so gloomy and irreversible that the average citizen’s response is to go out and buy a can of beer. If nothing can be done to escape the onward rush of some irreversible eco doom, then why take the trouble even to return the can? But indeed over a vast range of environmental problems, action is possible, polices are available, reversals can take place, water can run clean, the sun shine over clear cities, the oceans cleanse our human shores and harvest ripen in uncontaminated fields.” Ward and Dubois (1972).

• 18 storey building

• Narrow floor plan

• Stack ventilation on the rear

• Use of raise floor for nat. vent distribution.

• Innovative façade design

Federal Building, San Francisco.

Stattdor Building, Dusseldorf

•Double façade nat. vent

Air flow from outside to inside and then back out again

Nottingham University, UK.

• Nat. vent as architecture

• Wind scoops have a large potential application with high rise buildings

Liberty Tower, Japan.

Opening for Wind Floor

Natural ventilation strategies….

• Narrow floor plates

• Stack design

• Special facades

• Double facades

• Roof top ventilation devices

• Wind floors

• But in NZ there are minimal high rise examples

…But the first step is clear – reduce energy consumption. We must locate, orientate, insulate, naturally ventilate and daylight our buildings better.”

Graeme Robertson (1991)

Natural Ventilation Potentials in NZ

• Auckland 10%-12% potential

• Christchurch 2% - 3% potential

• Wellington 0% potential

Every 1% is equivalent to 15 minutes/day, every day.

• the economic reality that designers face summed up by Bosley commenting on the design of the Te Papa New Zealand’s National Museum “…we have choices, that is obvious. One of the problems of some projects is that the client defines a whole lot of things that limit incredibly the exploitation of what the building can be. You don’t have to accept that- you just don’t get the job.”

Is Sustainability sustainable?

• “…the concept of sustainability has developed considerably since its introduction by the Brundtland Commission in Our Common Future. It is now used by professionals throughout society for many purposes and with many meanings, each delivering a subtly different connotation to the term. Overall, however, there is agreement that inter- and intra-generational equity are important and that sustainability of environment, society and economics are also important. The complexity of sustainability is recognised but not yet fully understood…” Boyle 2004.

Conclusion on sustainability.

• There are definite potentials for using natural ventilation in high rise buildings in NZ.

• But unfortunately this is not happening even to the first level suggested by Robertson 13 years ago

• Therefore it is not possible to consider the even more complex levels suggested by Boyle this year

• Thus, it does appear that we “are not returning the can” as Ward and Dupois suggested 22 years ago.

• NZ high rise buildings are falling behind other countries.