Officials are advising that landlords may choose to exit the rental market and opt to put their property on Airbnb as a result of new minimum rental standards.
They have also warned Housing Minister Phil Twyford that low-quality rental properties were more likely to be sold off, as it would be too expensive for landlords to comply with the rules.
Act leader David Seymour says it was concerning that, in the middle of a housing crisis, the Government had decided to make it harder for those providing housing.
Yesterday, Twyford announced that from 2021, all private rental homes would be required by law to have a heater that can heat a main living area to 18C.
Kitchens and bathrooms will be required to have extraction fans or range hoods and the minimum level of ceiling and underfloor insulation would need to be at least 120mm thick, or meet the 2008 Building code.