The country's leading building product assurance scheme is in disarray after another major company pulled out of it.
The government's CodeMark scheme provides product approvals that cannot be challenged by councils during building consenting, but the scheme has now lost three of its seven certifiers, and these three have issued almost 70 percent of all certificates.
The latest to go is also the biggest, CertMark of Queensland, which issued 63 certificates, or a third of the total 183 CodeMarks.
It's a blow that the Building Industry Federation, which represents thousands of products suppliers, believes might prove fatal.
"CodeMark is broken," federation chief executive Julien Leys said.
"I think they [the government] need to really start from scratch."
CertMark has not responded to RNZ's queries.
It has faced a series of setbacks recently: Many of its CodeMark certificates for aluminium panel cladding were suspended last year for making unsupported fire protection claims, amid heightened scrutiny after the fatal Grenfell Tower fire in London; and the firm itself was suspended from CodeMark earlier this month for failing to follow the rules.
Thousands of buildings in New Zealand have CodeMark products in them, and thousands of building owners choose to use CodeMarked products as an accelerated route through council consenting.
The scheme itself was severely faulted in an internal review that RNZ fought MBIE to release last year.
But any certificates issued under it are still valid.
The country's biggest building consent issuer, Auckland Council, is still accepting them.
"In fact, Auckland Council is unable to refuse a CodeMark, including one issued already by CertMark," the council's general manager of building consents, Ian McCormick, said in a statement.
"You have asked if it is prudent for [the council] to continue to accept CodeMark certificates from CertMark," Mr McCormick told RNZ.
"Unless a CodeMark is withdrawn, there is no discretion for the council or any other council in New Zealand to refuse that certificate so long as the design or product used complies with the terms of that CodeMark certificate.
"... the council is supportive of a robust product assurance scheme. However, that support does not preclude the need to ask questions or require information on specific certificates from time to time as some CodeMark certificates contain conditions that we need to be satisfied have been met."
Manufacturers and suppliers pay certifiers tens of thousands of dollars for a CodeMark.
CertMark's 63 certificates risk being withdrawn unless another certifier steps in to pick them up and do the annual audit that's required.
The CodeMark scheme's manager, the Joint Accreditation System of Australia and New Zealand or Jas-Anz, is asking other certifiers to help.
"Luckily, at the moment there aren't a large number of certificates so the remaining four [certifiers] should be able to cope," Jas-Anz's Steve Keeling said.
"Although the [certifiers] are required to co-operate, they are not obliged to accept any certificates that have not been issued on solid evidence."
But with just four of the less active certifiers left in CodeMark, ex-certifier Colin Prouse has grave doubts.
"It's going to be difficult to see how all of those certificates that CertMark have in New Zealand are going to be dealt with in a proper manner, bearing in mind that there aren't many others who could deal with all of those certificates in what would appear to be a relatively short time frame," Mr Prouse said.
His Wellington firm Beal was forced out of CodeMark by MBIE late last year over quality concerns. Mr Prouse said that was not deserved.
Beal had by then issued the second largest number of CodeMark certificates, 31.
"I do know that a number of our certificate holders have been looking at both CertMark and the likes of [CodeMark certifier] Bureau Veritas," Mr Prouse said. "There's been all kinds of challenges based on the limited resources that they have.
"My understanding it's going to cost them [holders] a lot of time and a lot of money."
A third company, the state-owned AsureQuality, stopped issuing CodeMarks off its own bat last year; it was the third largest issuer.
Auckland building product supplier Jason Bardell held an AsureQuality certificate and had to find another certifier to audit it.
"There was time and money and cost involved in that process but no more than the usual annual audit cost," Mr Bardell, who runs Independent Building Supplies, said.
"That process for us has been, I wouldn't say easy, but certainly AsureQuality did everything they could do to make it as seamless and as painless for us as possible."
However, another player in the market, who RNZ agreed not to identify, said holders of CertMark certificates might run into bigger problems.
"There is absolutely no way that the current four certifiers have the capacity to take over these certificates even if the compliance folders were absolutely complete."
Mr Bardell remains a big fan of CodeMark, saying it was far more rigorous than getting a product appraised, such as by Branz, and it just needed streamlining to make it quicker and cheaper to get a product certified.
He still aims to get another product CodeMark-certified this year, and another next year.
However, no-one was helping suppliers get innovative products assessed, without having to incur major appraisal costs, and MBIE should do this, Mr Bardell said.
Mr Leys said suppliers and the public needed a scheme they could trust, and he cited the fatal Grenfell fire as an example of having product quality checks that were too loose.
"Grenfell is just a catchcry as to why we need to really get on with this. We need to have a system in New Zealand that works, that people can trust and have faith on."
The Ministry of Business, Innovation and Employment declined to make someone available to interview.
It is overhauling the Building Code, including how building products are policed. Previous attempts to do this have stalled.