New condensation in buildings handbook

The NCC 2022 condensation management provisions build on the NCC 2019 provisions to further reduce the risk of condensation in new homes. An overview of these NCC changes is in this article.

An updated Condensation in buildings handbook is now available. It provides further support to practitioners on using the new condensation management provisions in NCC 2022.

The handbook introduces the concept of condensation, its causes and consequences if left unchecked. It expands on the regulatory requirements of the NCC with non-mandatory guidance for designers, builders and occupants on other potential strategies to consider.

Here’s some tips to get you started, with more information in the handbook.

• Choose appropriate materials and construction details that account for local conditions. This is because the risk and causes of condensation vary according to the local climate in which the building is being constructed.
• Consider whether vapour may get trapped within any parts of the walls and roof and whether there is sufficient ventilation in areas of extreme moisture.
• Consider the number of occupants and sources of internal water vapour at the design stage. This includes water vapour sources such as showers, cooking, laundry drying, etc.

• Pay careful attention to ensure the correct installation of building materials, particularly materials used to control vapour within walls and roofs.
• Communicate the condensation control strategy to workers on site. Also advise other trades (particularly services installers) to help avoid unintentional disruption of a condensation control strategy.
• Before handover, advise the building users that construction moisture may take about a year or more to dry out.

• Open windows or doors periodically. This contributes to efficient and cost-effective natural ventilation that will reduce the amount of water vapour circulating indoors.
• In cooler seasons, consider opening your windows in the afternoon when daytime temperatures are highest.

A webinar series was held in March 2023 to support the new condensation management, energy efficiency and livable housing provisions. Visit the ABCB's YouTube channel to view the NCC 2022 Webinar Series: condensation management video. 

Further tips and guidance on managing condensation are also available from YourHome.

This page was updated on 29 July 2024.