If you've ever wondered about the risk of a fire in a crowded carparking building, three New Zealand engineering students may soon be able to give you a clear answer.

The Canterbury University students are surveying parking buildings at two hospitals and two shopping malls in Christchurch to measure how full they are, how often cars are coming and going, and the layout of cars in the carpark.

Their supervisor, Associate Professor Mike Spearpoint, says the research is likely to show that engineering for fire containment should probably vary depending on all these factors. Very full and busy carparks where the cars are packed densely together are likely to need more stringent fire safety design.

"There is not much data on this when you look at the academic literature. That says how few people have measured this," he said.


He said carpark fires were not common, but when they happened they could spread quickly and cause major damage.

"It's not just the fuel. There is all the upholstery in the vehicle, the seats, all that sort of thing, and they give off quite a lot of horrible smoke," he said.

Simple design factors, such as whether cars are in single lines or parked facing each other in double lines, could make a big difference.

"A vehicle in a double line has five neighbours around it," he said. "If you have a single row the vehicle that catches fire has two neighbours.

"But it would be very surprising if people designing carparks designed them just for fire safety. There are lot of other efficiencies they have to design for in terms of carpark design. So it's not about redesigning carparks, but thinking about if a carpark is designed with single rows, should the fire protection solution be different?"

Doctoral student Zahir Tohir is developing a model of all the important factors. He had originally planned to test it against actual data from major parking buildings in Auckland, but Dr Spearpoint said Wilsons Parking refused to provide data on grounds of commercial sensitivity. Auckland Council agreed to provide data on its parking buildings but so far had not actually provided any.

So he asked two final-year honours students Cole Anderson and Nic Bell to survey Christchurch parking buildings directly by walking around the carparks at different times of the day and noting how many cars were parked, where they were parked, and how often they moved.

The two students will present their study to the university's annual civil and natural resources engineering research conference on campus next month (October 18).