Testing of a spray-on, water-proof membrane to protect flood-prone homes has begun in Christchurch.
Areas such as the Flockton Basin have been more susceptible to floods since the Canterbury earthquakes shifted ground levels and lowered houses.
The coating is being tested on a red-zoned property in Christchurch East over the next few days.
An embankment around the house will be filled with water to simulate flooding to the levels reached in March and April this year.
The council manager in charge of the project, John Mackie, is optimistic about the method.
"I'm 90 percent confident right now, because the proof concept has worked in the UK, just given that little risk around the New Zealand building approach - we have different design standards, different soil types.
"There is an element of risk that this may not work, so I'm not going to be here red-faced if it doesn't, because you learn from your mistakes."
It could be an effective flood protection method, at a cost of $15,000-$20,000 per house, Mr Mackie said.