The government has announced a new scheme to accelerate building projects with self-certification and inspection targets.

It means approved building firms, plumbers, and drainlayers will be able to sign off their own work.

Building and Construction Minister Chris Penk made the announcement on Monday from Waitoki, north of Auckland.

"Making it easier and more affordable to build opens the door to homeownership for more Kiwis, gives families choice about where they live, and supports growth and job creation in the construction sector," Penk said.

"We can't achieve this vision while the building consent system remains slow and overloaded. Even simple, single-storey homes must go through around 12 inspections before they're finished, with costly delays when demand is high."

Penk said the announcement came at a time when many Kiwis were locked out of the housing market.

He said the government is committed to making the building system more efficient and that Cabinet had agreed to an opt-in self-certification scheme, which would allow approved building firms, plumbers, and drainlayers to sign off their own work.

"Reputable building companies delivering large numbers of near-identical houses each year will be able to proceed without the need for Building Consent Authorities (BCAs) to approve a building consent and carry out inspections," he said.

"Giving qualified plumbers and drainlayers the ability to self-certify their work puts them on equal footing with electricians and gasfitters, who've had that flexibility for years. It's a common-sense change backed by Master Plumbers and delivers on a National Party campaign promise."

Penk said Kiwis should have confidence that their homes are built to a high standard, and that is why only proven professionals who meet strict criteria will be eligible for the scheme - and only for simple residential dwellings.

He said the changes initially would result in around 3000 homes built each year without delays from approvals or inspections.

"In addition, the government will require BCAs complete 80 percent of building inspections within three working days," he said.

Disruptions to project timelines

Master Builders welcomed the announcement as a meaningful step toward reducing inspection delays, Penk said.

He said they regularly hear from frustrated builders, with disruption to project timelines creating uncertainty for homeowners.

Wait times sometimes stretch up to a week - having a knock-on effect which can add about $400 for every day a project is held up, he said.

"Updated guidance will be issued to BCAs, outlining practical strategies to boost efficiency, reduce bottlenecks, and help authorities better prioritise their workloads," he said.

"BCAs success in meeting the target will be shown in quarterly performance data - giving the public greater transparency and encouraging improved performance."

Penk said by backing skilled professionals and focusing council resources, they can cut building costs without sacrificing quality and deliver more affordable homes.

Inspection targets will come into force later this year and legislation to enable the self-certification scheme will be introduced by the end of 2025.

Earlier in April, the coalition government announced it would be increasing the maximum size of granny flats allowed to be built without consents, as part of changes to be introduced to make it easier for people to build standalone dwellings on their properties.