Housing Minister Chris Bishop has written to the board of Kāinga Ora Homes and Communities to make clear he expects social homes not to be left empty longer than absolutely necessary.
In the letter, Bishop said the number of social houses sitting vacant was completely unacceptable.
"I wish to make clear my expectation that, with over 25,000 people on the social housing waitlist, social houses owned by Kāinga Ora are not to be left empty for a day longer than absolutely necessary. It is my expectation that Kāinga Ora works with much greater urgency to fill its vacant homes," Bishop wrote.
"While I understand there may be instances where, for valid reasons, it takes time to fill a vacant home, the timeframes identified in this response are well beyond what I consider appropriate."
He said he had been "shocked" to discover through an Official Information Act response to Stuff reporter Erin Gourley that 3906, or about 5 percent, of New Zealand's total housing stock was vacant.
Some 786 - almost 20 percent - of the new public homes built by the government's social housing landlord and construction agency between June 2022 and October last year were also still vacant by the end of October.
"It's simply not okay," he said. "Of these new homes, 287 were empty for more than four months despite thousands of families waiting for social homes such as these."
His letter said it was "unacceptable that people needing a social house are waiting in motel rooms, in cars and on family members' couches while newly built social housing units sit empty".
"I expect Kāinga Ora to be working through the social housing waiting list alongside MSD with utmost urgency to ensure as many families as possible have safe, warm, dry homes to live in."
Bishop told reporters he had been "incredibly frustrated by Kāinga Ora for a long period of time now" and he expect them to the necessary make changes with urgency.
"One of the explanations given is that Kainga ora likes to move people into new housing developments gradually. Frankly I think that's just unacceptable.
"We need vacant homes to be filled with people who are in severe and urgent need of housing - that's how you get on the register in the first place, you need a house. You might be living in a motel or you might be bunking with firends and familybut you need a social house."
He said taxpayers were entitled to expect that when there was a vacant social house owned by the government, then people in urgent need of housing were moved into that house as soon as possible.
The government a month ago also set up an independent review headed by former prime minister Bill English to look into the agency's financial situation, procurement and management, which is due to report back before April.
Bishop said he was looking forward to receiving the report.