Compulsory licensing for builders and the possible banning of some construction methods are among changes expected in the review of New Zealand’s Building Act, initiated in response to the country’s leaky homes crisis.

Poor design and the use of untreated timber in framing have been blamed for the crisis, which has left homeowners’ repair bills reaching NZ$240m.

The review is designed to improve construction quality and provide safe homes for people. But, according to some estimates, the changes could add about 2.9% to the costs of homes.

Better building controls and more reliable inspections are also expected in the new legislation.

The chief executive of a new department which will replace the Building Industry Authority is to oversee the drawing-up of a new building code.