Despite a record number of consents for new homes issued last year, construction could still be delayed due to lack of workers and materials, builders say.
There were 48,522 new homes consented in the year to November 2021.
Building Industry Federation chief executive Julien Leys said the industry would not be able to build all of them.
"It's great on one level to have a record number of consents for new houses, which is what we need, but we have to accept the fact that we don't have enough builders or in fact materials."
Leys said in times without Covid-19 or other disruptions New Zealand built only 40,000 homes per year.
Some builders were booked up for the next 12 to 24 months and there was a lack of skilled workers, such as carpenters, quantity surveyors and truck drivers, due to border restrictions.
Leys said the last 18 to 24 months had been a "perfect storm" during which builders were also waiting longer to get timber, timber frames and other materials.
"The industry is going through a boom period. The unfortunate fact is that builders are having to turn work away and people that have got some of these consents are either going to have to wait a very long time if they're lucky, or in some cases, the houses just won't get built, unfortunately."
Leys said many builders were planning ahead and placing orders for materials much earlier than before, though some were struggling with cash flow.
He said the government should allow more skilled workers to come through the borders.
"The challenge we've got in 2022 might well be even more significant than the challenges we had last year, and I think this year 2022 is going to be about shortage and lack of skilled people rather than the shortage of building materials."
Auckland-based Chancellor Construction director Wayne Zeng said many consents are for high-density housing.
"What it means to us is there's more work comparing to a few years ago where builders were building larger homes and now we're building smaller homes."
That required more resources, skilled workers and materials, he said.
Zeng said although the issues were the same as those facing many countries amid the Covid-19 pandemic, there were things the authorities could do to help.
"Local council authorities could consider more substitutions and flexibility around material supplies, and re-engineer and re-look at the current building code to help the builders."
Builder Richard Merrifield, based in Nelson, agreed the industry was facing challenges and said the authorities should encourage innovation.
"Do we keep building houses the same way we have for years or look at more innovative ideas? There are some bright young people around the industry that will be thinking outside the square, that will come up with solutions to these problems."
Building and Construction Minister Poto Williams expected high levels of residential construction to continue for some time.
She said the government would continue to work with the sector to help minimise disruption from Covid-19.