A homeowners lobby group helping apartment owners with repairs and litigation says the next government will need to face up to a growing crisis over substandard buildings.

The repair bill on two big Auckland apartment blocks is growing by millions of dollars as more poor construction comes to light.

The Home Owners and Buyers Association, which is involved in the repairs, said it was also aware of half a dozen new apartment blocks in the city with deficient weathertightness, fire protection or other building work.

"We've got a lot of people where their wealth has been undermined hugely by this - that's a major concern, which I feel the government has some responsibility [for] or should've done something about," the group's head, Roger Levie, said.

In Mt Wellington's Mountain View Apartments it was helping 99 unit owners with repairs after the builders completely left out planned fire-proofing of holes between apartments designed to stop smoke, hot gases and flames spreading. The bill there is now above $35 million, up from $33m a few months ago.

At a 285-unit St Lukes Garden complex in Mt Albert - a cluster of concrete towers built between 2002 and 2011 - a stopgap repair to a serious structural issue has allowed owners to keep living in it.  The estimate for repairs there - which haven't begun yet - is $65m and climbing. The association is helping the owners sue Auckland Council.

Mr Levie said that for both St Lukes and Mountain View, the building contracting companies involved no longer existed, though some of the individual builders at the St Lukes project were still operating today.

The council's systems were better but the record-keeping of construction monitoring was poor, and bad work was still slipping through, he said.

In the case of the half-dozen new blocks where owners had come to the association asking for help recently, Mr Levie said there was no threat to human life from the deficiencies.

It could, however, be very hard to tell with fire protection work, because it was difficult to see what was missing or done wrong without invasive checks inside ceilings and walls, he said.

The association has had direct involvement in 50 multi-unit projects and knew of another 80 blocks with issues, mostly in Auckland, he said.

Claims have been lodged with the Weathertight Homes Resolution Service for almost 13,000 properties nationwide.

Mr Levie estimated that constituted just 15 percent of dodgy apartments and houses.

"Take Mountain View - 99 units, at one stage everybody was out, so they all had to go and find somewhere else to live ... and that's being multiplied across Auckland, so in terms of the housing crisis, it's a big issue."