Reform of the building consent regime will mark the beginning of a "new era for the construction industry", a developers' lobby group says.

The government announced on Sunday it would be reforming the building consent system - including reducing the number of consenting authorities.

It was also looking at changing who was legally responsible for payouts over defective buildings.

The announcement followed proposed 'granny flat' law changes that would remove the need for consents for homes under 60sqm.

Minister of Building and Construction Chris Penk said the "cumbersome" consenting system meant New Zealand had some of the "least affordable housing in the world".

The system was intended to protect homeowners from defective building work, by requiring it to be inspected and consented by a Building Consent Authority (BCA).

A lack of consistency in how the 67 BCAs were interpreting the building code was leading to costs and delays for builders, he said.

Among the new options being considered to replace the current BCA system were:

• voluntary consolidation: allowing councils to pool resources for building consents
• regional BCAs: establishing a smaller number of regional BCAs
• single point of contact for builders to submit plans to: inspections may be contracted out to existing BCAs or private consenting providers, "creating competition and encouraging specialisation".

The government was also looking at changing who was legally responsible for payouts over defective buildings.

"Under the current settings, councils and their ratepayers are liable for defective work," Penk said.

"Joint and several liability means councils can be 'the last person standing' available to foot the bill when things go wrong. This creates a highly conservative and risk-averse approach, which contributes cost and draws out deadlines."

Property Council NZ chief executive Leonie Freeman. PHOTO: Richard Doran Photography

Property Council chief executive Leonie Freeman welcomed the changes as a "bold move", saying they would cut through red tape and deliver faster, more efficient developments.

"Our members, including the country's leading property developers, investors, managers and property experts, have been clear: the current consenting system is plagued by delays and inconsistencies across regions.

"It's hindering progress and escalating costs for projects that are crucial to meeting New Zealand's housing needs."

Developers had reported wait times over two months for building consents, and up to 18 months for resource consents, she said.

"This creates a level of uncertainty that drives up costs, slows progress and ultimately puts home affordability further out of reach."

Read more:

The announcement marked "the beginning of a new era for the construction industry", and the group had been "actively engaging" with the government on the issue all year, she said in a statement.

"We are fully supportive of the options presented today. Faster, streamlined consents mean faster, more affordable housing, which benefits everyone," Freeman said.

An advocate for owners of leaky homes said the government needs to be cautious around any re-introduction of private building consent providers.

The president of home owners and buyers association, John Gray, said this was practiced in the 1990s and owners had suffered from the providers' lack of competency.

"It did not work then and it will not work now, unless they get competent people.

"And most importantly, that those private certifiers have mandatory insurance to back them for their failures."

Gray said many private certifying companies went bust in the '90s because no insurers were prepared to take the risk of insuring them.

'Go harder' on building reforms - ACT

Meanwhile, the ACT party urged the government to "go harder" on its reforms.

ACT housing, building, and construction spokesman Cameron Luxton said the government should also look at letting home builders opt out of building consents, provided they had long-term insurance for the work.

"That would get councils out of the way completely, for faster, more innovative, and ultimately more reliable building consents."