Labour says it can fix unhealthy and cold houses that are to blame for child deaths in New Zealand in its first 100 days if elected in September.

Housing spokesman Phil Twyford made the commitment to set minimum standards for rental properties within the first three months of a Labour government.

The promise came on Wednesday after a report by the NZ Herald that 20 children a year died from preventable illnesses linked to poor quality housing.

READ MORE: Crowded, damp homes killing 20 kids every year

Since 2000 more than 350 have died, according to figures obtained by NZME.

"This is a moral issue - we should not be the kind of society that lets children die from preventable diseases. We are better than that," Mr Twyford said.

On twitter he added: "We'll fix this in our first 100 days".

We'll fix this in our first 100 days. https://t.co/K4dnPOnOVW

— Phil Twyford (@PhilTwyford) August 29, 2017

Labour would require landlords to ensure houses meet minimum standards in insulation, heating and ventilation.

The standards are in a member's bill by former Labour leader Andrew Little, which is currently before parliament.