Home air sealing and ventilation

Last updated: 6 September 2022

What is air sealing?

Air sealing is the prevention of excess air movement from inside to outside your home. Limiting air loss through gaps and cracks will save you energy and reduce your heating costs during winter. Air sealing should always be partnered with natural ventilation, which allows you to control the flow of air when and where you want it in your home.

Air sealing your home

There are two ways you can air seal your home:

Draught proofing

Draught proofing, or sealing up gaps and cracks, will minimise heat loss from your home and reduce your heating bills. There are several easy ways to find draughts in your home.

Vapour barriers

A vapour barrier is an air sealing membrane that prevents internal air from escaping outside. This is particularly beneficial in winter to keep warm air inside the home. After installing bulk insulation to internal walls, a vapour barrier can be created by wrapping a continuous seal around the insulation before replacing the plasterboard lining. Once the airtight vapour barrier is in place, it is sealed with tape, seals and glue, especially where pipes or cables penetrate.

Ventilating your home

Ventilation is also an important way to regulate your home's air temperature and keep it free of condensation build-up which can result in mould, rot or damp. In temperate climates a combination of air sealing and ventilation will create a healthier indoor environment by removing warmer, humid air and replacing it with cooler, drier air.

There are three main ways to ventilate your home:

Open it up

The easiest and most cost-effective way to ventilate your home is to open it up when the outside temperature is comfortable. Cool down your home in summer by opening doors and windows at opposite sides of your house.

Plan for cross-ventilation

When building or renovating, plan for cross-ventilation from front to back, and between each side of the house. During hot summer days, cross-ventilation will allow you to take advantage of the cooling southerly breezes of early evening.

Mechanical ventilation

Mechanical ventilation technology ensures that your home receives a constant flow of clean, cool air to replace stale, warm and humid air.

Questions to ask your builder

Although it is possible to install air sealing measures yourself, trained professionals may be able to:

  • more accurately measure the levels of air leakage in your home
  • ensure that your air sealing offers greater energy (and money) savings in the long term.

Building or renovating?

If you're building a home or undertaking a renovation, you might like to refer to our list of questions to ask your builder, architect or installer.

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