Simple Ways to Lower Energy Bills: Dampness & Ventilation

Information sourced from, an EECA initiative.


Dampness and lack of ventilation are problems faced by many Kiwi households come winter and wet weather. However, by taking simple precautions and measures, you can prevent them and save your house from long term problems.

Diagnosing the problem

But first, let’s find out if your house is showing any warning signs of dampness. The common signs of dampness are: 

  • Mould, stains and watermarks on the walls or ceilings
  • Musty smells
  • Rotting wood in your house’s framework
  • Mould under the house

If you notice any of these in your house, your place is probably not dry ventilated enough.

Finding solution & taking precautions

There are several ways to tackle this problem. Here are a few things you can do inside the house:

  • Dry washing outside. Line drying your washing outside on a sunny day or using a dryer can make sure moisture doesn’t build up inside
  • Use extractor/exhaust fans in bathrooms to release excess steam and moisture outside
  • Allow cross ventilation when possible, leaving windows and doors open to let the wind carry out excess moisture
  • Use a heater to keep interiors warm; this prevents mould from growing
  • Avoid unflued gas heaters as they release moisture and toxic gases into your house. Plus they can also be fire hazards
  • Use a dehumidifier in tandem with a heater to heat the room faster.
  • Keep furniture away from walls; a 10 cm gap can prevent mould from growing behind it
  • Use a bed base leaving mattresses on the floor prevents air flow underneath it.

And here are some steps you can take outside:

  • Check plumbing for leaks, especially near showers, baths and under the house
  • Install a ground moisture barrier on the ground under your house. This prevents moisture from rising into the air underneath the house. See how you can do it here
  • Check for blocked pipes and gutters, and that these are connected to the stormwater drains
  • Check vents, and keep them clear of obstructions for good air flow

Do a free check to see if your home is dry, warm and healthy with HomeFit. 

You can help make a difference!

Help to keep thousands of Kiwis experiencing hardship warm this winter by making a donation to Whānau Āwhina Plunket and Variety - the Children's Charity.