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Leaky buildings and weathertightness

This section links to useful information on our ConsumerBuild website [External website]. about leaky buildings, and what you can do to prevent problems, including engaging a competent architect or designer.


ConsumerBuild is an easy-to-use website with a wide range of clear, independent information. It was developed as a partnership between the Department of Building and Housing and Consumers' Institute.

Background to the problem

We explain why there are leaky homes in New Zealand and identify the main causes of leaking. Read more about the background [External website]. .

Addressing the problem

We look at what measures have been taken to ensure houses, units and apartments are built to ensure weathertightness, including the detailed weathertightness solutions and changes to New Zealand’s timber treatment requirements. Read more about addressing the problem [External website]. .

Building a new home

Essential information you need if you are building a new home. We discuss the 4Ds of weathertightness design and how to include these principles in your design to make sure your home will be weathertight. Topics covered: Read more about building a new home [External website]. .

  • Introducing the 4Ds of weather management
  • How much detail do you need to know?
  • Design to deal with external moisture
  • Explaining cavities
  • Timber treatments
  • Choosing the right materials
  • Building consent and code compliance certificates

Maintaining your home

If your home could have issues with weathertightness, you need to be especially vigilant in your maintenance checks - particularly in regard to potentially unsafe balconies, balustrades, decks, car decks and mould. Read more about maintaining your home [External website]. .

Topics covered:

  • Checking for moisture
  • What to do if you find problems
  • Balconies
  • Dealing with mould
  • Maintaining open timber decks
  • Maintaining car decks
  • Does work on a deck or balcony require a building consent?
  • More information

Buying an existing home

We suggest what to look for when buying a home to avoid problems with weathertightness. Read more about buying an existing home [External website]. .

What to do if you have a leaky home

What can you do if you discover your home has problems with leaking and weathertightness? We look at the options, including using the Weathertight Homes Resolution Service. Read more about what to do if you have a leaky home [External website]. .