A Labour-led government would set tough minimum standards to make all rental properties warm and dry in its first 100 days.
The issue of warm housing is front and centre in Auckland after revelations more New Zealand children were killed by diseases linked to cold, damp, and overcrowded housing than in car crashes or drownings.
Mr Twyford said he was sick of hearing the excuses from National for not doing anything while it cut money for home insulation and blocked Labour's attempts to set proper health standards for rentals.
''I'm tired of knocking on doors and finding overcrowded homes with unwell children because rents for anything better are too expensive.''
Labour would require all rentals to be warm, dry and healthy to live in, he said.
It would help families meet their heating costs with a $700 winter energy payment for beneficiary families and boost family incomes with the Best Start payment, increase Working for Families and boost the accommodation supplement.
Landlords and homeowners would be helped with $2000 grants for insulation and heating.
Labour would address the housing shortage that was driving up rents by stopping the state house sell-off and building new state houses for families in need, Mr Twyford said.
Act New Zealand leader David Seymour said a story out of Auckland about sleeping pods advertised at $200 a week showed how absurd New Zealand's housing crisis had become.
But even more distressing was the report showing damp houses killed more children than car crashes.
''The housing crisis actually has a body count. Landlords know they can get away with squalid conditions because during a housing shortage, tenants will take what they can get.''
New Zealand's top civil servants seemed to be focused on sharing gossip with ministers when they could use some of their briefings to address the fact there was an appalling housing shortage, he said.
Act would be making the case that only a massive increase in the rate of home building would turn a landlord's market into a renter's market, improving affordability and quality across the entire rental stock.
