Rental homes must have openable windows in the living room, dining room, kitchen and bedrooms. Kitchens and bathrooms must have appropriately sized extractor fans.

Mould and dampness caused by poor ventilation is harmful for tenants’ health as well as landlords’ property. The ventilation standard targets mould and dampness in rental homes.

Mould and dampness

All private rentals must comply within 90 days of any new or renewed tenancy after 1 July 2021, with all private rentals complying by 1 July 2024.

 All boarding houses must comply by 1 July 2021. All houses rented by Housing New Zealand and registered Community Housing Providers must comply by 1 July 2023.

What is the ventilation standard?

All habitable rooms in a rental property must have at least one window, door or skylight which opens to the outside and can be fixed in the open position.

In each room, the size of the openable windows, doors and skylights together must be at least 5% of the floor area of that room.

Each window door, window or skylight must be openable and must be able to remain fixed in an open position.

All kitchens and bathrooms must have an extractor fan vented to the outside.

  • Kitchens – In any room with a cooktop, new fans or rangehoods installed after 1 July 2019 must have a minimum diameter (including ducting) of 150mm or an exhaust capacity of at least 50 litres per second.
  • Bathrooms – In any room with a shower or both, new fans installed after 1 July 2019 must have a minimum diameter (including ducting) of 120mm or an exhaust capacity of at least 25 litres per second.

Landlords should ask installers for the details of the fan diameters, ducting and flowrate in writing, so they can show they are compliant with the healthy homes ventilation standard.

If you have an existing fan

Fans put in before 1 July 2019 must ventilate to the outside the house and be in good working order, but they don’t have to meet the requirements listed above.

When they stop working, they must be repaired to be in good working order or replaced with fans which do meet all the requirements.

Exemptions to the ventilation standard

There are two specific exemptions to the ventilation standard.

A room is exempt from the openable windows requirement if it met legal requirements when it was built or converted, even if it did not have an openable window in that room. It must continue to meet those requirements.

There is also an exemption to installing extractor fans where it is not reasonably practicable to do so.

It is not reasonably practicable to install something if a professional installer can’t access the area without:

  • Carrying out substantial building work, or
  • Causing substantial damage to the property, or
  • Creating greater risks to a person’s health and safety than is normally acceptable, or
  • It is otherwise not practicable for a professional installer to carry out the work.

These are in addition to the general exemptions.

General exemptions to the healthy homes standards

Further information

Useful tips for ventilating your rental home

The ventilation standard is one of five healthy homes standards.

Find out about the other healthy homes standards: