Buildings Up To Wind
Better understanding of the effect of New Zealand's wind on buildings is leading to the construction of less expensive but equally safe buildings.
The results of research by scientists in Lower Hutt have been considered in the draft Australia-New Zealand wind loadings standard, which was issued in 1999, and have also been included in the designs of new buildings. The research was funded by an investment from the Foundation for Research, Science and Technology.
"Wind affects the lives of all New Zealanders," Opus Central Laboratories researcher Paul Carpenter says. "For some, our relatively windy climate is just a nuisance, but wind damage has been estimated to cost the country $20 million a year - and its benefits, such as conversion to electricity, should not be overlooked."
The research team has produced new information on hill shapes and the wind.
"The rules about wind, buildings and hills have generally been based around idealised hill shapes," Mr Carpenter says. "That makes it easier to work out wind loadings on buildings on hills.
"But it's not entirely accurate. Hills are complicated - in real life they're all sorts of shapes. That's meant the wind-loading figures have not been accurate."
Because of that lack of knowledge, some buildings in New Zealand have been constructed to higher specifications than necessary. On the other hand, he says, some buildings that have been put up in high-wind areas have not been strong enough. Special care needs to be taken when building at high-wind speed sites.
"We've looked at the physical environment, building aerodynamics and wind speeds over hills, as well as studying people's tolerance to winds they encounter in city streets, and the effects of wind-breaks.
"Cheaper and safer housing and commercial buildings can now be built because the wind loads on buildings are better understood," Mr Carpenter says.