There must be windows, skylights or doors that open to the outside in the living room, dining room, kitchen and bedrooms. These must be able to be fixed in the open position and comprise at least 5%  of the room’s floor area. There must be extractor fans in kitchens and bathrooms that vent 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 bath, 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.

Rental properties must have efficient drainage for the removal of storm water, surface water and ground water, including an appropriate outfall. The drainage system must include gutters, downpipes and drains for the removal of water from the roof.
If the rental property has an enclosed subfloor, a ground moisture barrier must be installed if it is reasonably practicable to do so.
A ground moisture barrier is generally a polythene sheet that can be bought from most building retailers. It can be installed by a house owner or a building professional.

Ground moisture barriers must either:
Have a vapour flow resistance of at least 50MNs/g and be installed by a professional installer and be beea polythene sheet and installed in accordance with section 8 of New Zealand Standard NZS4246:2016.

Under the Healthy Homes standards, landlords must make sure the premises doesn’t have unreasonable gaps or holes in walls, ceilings, windows, skylights, floors and doors which cause noticeable draughts. Landlords can’t use the age and condition of the house as a reason not to stop gaps or holes. If rental homes have an open fireplace, it must be closed off or the chimney blocked to prevent draughts in and out of the property through the fireplace. Tenants can ask landlords in writing to make the fireplace available for use and the landlord can agree. If it is available for use, it must be in good working order and free of any gaps which could cause a draught that are not necessary for the safe and efficient operation of the open fireplace. It is best practice to record any agreement in writing, with both tenant and landlord keeping a copy.

There must be one or more fixed heater(s) that can directly heat the main living room to at least 18°C. Certain heating devices that are inefficient, unaffordable or unhealthy will not meet the requirements of this standard.

Your heater must not be an open fire or an unflued combustion heater, eg portable LPG bottle heaters. If you use a heat pump or an electric heater, it must have a thermostat. You can’t use an electric heater (except a heat pump) if the required heating capacity for the main living room is more than 2.4 kW, unless you’re ‘topping up’ existing qualifying heating that was installed before 1 July 2019. In most cases, the right type of heater will be a larger fixed heating device like a heat pump, wood burner, pellet burner or flued gas heater. In some cases, eg small apartments, a smaller fixed electric heater will be enough.

Some existing insulation will need to be topped up or replaced. Depending on location, ceiling insulation needs to meet minimum R-values, or existing ceiling insulation needs to be at least 120mm thick. Ceiling insulation needs an R2.9 rating, underfloor insulation needs a minimum R-value of 1.3.
All existing insulation must still be in reasonable condition to meet the requirements. This means there should be no mould, dampness, damage or gaps.

Exemptions:
Access is impracticable or unsafe.
Partial exemption for some underfloor heating (certificate required).
Ceilings or floors with other habitable spaces above or below.