Healthy Housing

When a home is warm and healthy, it’s less likely that tenants will suffer health problems caused by cold and damp, such as respiratory illnesses like asthma, and other serious illness. This is particularly true for children, older people, or those who already have poor health.


Good quality insulation helps keep the heat in during winter and out during summer. New legislation requires that social housing (where tenants pay an income related rent) must be insulated prior to 1 July 2016 and all other rental homes before 1 July 2019. For more information on the requirements for insulating rental properties, please visit the Tenancy Services website.  From July 2016, grants have been available through the Energywise Warm Up New Zealand: Healthy Homes fund. The fund is designed to assist landlords to insulate housing stock built prior to the year 2000 and is for the installation of ceiling and underfloor insulation of rental properties occupied by low-income tenants. for more information regarding the funding and eligibility requirements, visit the Energywise website.


Ventilation is an important factor in creating a dry environment for residents to live in. You should think about how you can make sure the internal environment can be ventilated while keeping the house safe and secure while you are not at home, window stays can be good for this. Inadequate heating and ventilation can lead to mould growth and dampness.  To protect the health of everyone in your home, remove mould as soon as it appears. You could use diluted household bleach (1 part bleach with 3 parts water mixed together), or a less abrasive cleaner like cider vinegar, use a clean sponge or cloth when washing off mould and rinse it often to reduce the risk of it spreading. It is recommended that you wear gloves and a disposable face mask when washing it away.


Dampness is often from external sources – check that gutters are clear, downpipes and drainage are working. Where the house has a suspended floor, check that the ground is dry and that there are no leaks. Hidden sources of dampness left undetected long enough may cause expensive damage to a home.

Tips and actions

  • The simplest way to ventilate your home, even in winter, is to open the doors and windows regularly to allow fresh air in. Good ventilation is important for maintaining healthy indoor air and reducing the amount of moisture in your home will make it easier to heat.
  • Extractor fans that vent to the outside are good to have in wet areas of the home such as the bathroom and kitchen to help remove damp air. Bathroom extractor fans are often connected to the light switch so that they come on automatically and go off ten minutes after the light is turned off.
  • Dryers vented to the outside reduce the amount of moisture released inside the house.
  • Mechanical ventilation systems that source air from the outside may be a good option if tenants are out all day, and/or if the property is near a source of noise such as a busy road or airport. Some systems come with heat exchange units, which transfers the bulk of the heat from the outgoing air into the fresh air coming from the outside.
  • Unflued gas heaters release moisture and pollutants into the indoor air during combustion. Landlords may choose to ban the use of portable LPG cabinet heaters in the tenancy agreement.

Eco Design Advisor

Eco Design Advisor

The Eco Design Advisor website has a range of factsheets to assist you with implementing practical solutions to combat the cold and moisture including: