E2 External moisture

External roof, wall claddings and external openings will prevent external moisture from causing undue dampness or damage.

This clause requires buildings to be constructed to provide adequate resistance to penetration by, and the accumulation of, moisture from the outside.

It contains requirements for roofs, wall claddings and external openings to:

  • prevent water entry
  • prevent water absorption and transmission
  • prevent the accumulation of water
  • allow for dissipation.  

The clause applies to most buildings, as set out in the limit on application in E2.2.

The Acceptable Solution to E2 External Moisture, E2/AS1, is widely used for weathertight design. About E2/AS1 provides a general overview.

Record of amendments is a record of changes to the Acceptable Solutions, Verification Methods and handbooks.


Acceptable Solutions and Verification Methods

Current version

These are issued by MBIE to provide one way of complying with the Building Regulations and must be accepted by BCAs as demonstrating compliance with the related clauses of the Building Regulations. Using them is not mandatory.


Acceptable Solutions and Verification Methods (AS and VMs) were called compliance documents. Some still have the “compliance document” title but the AS or VMs they contain are valid and unaffected by the name change.

Previous versions


Standards are frequently referred to in Acceptable Solutions and Verification Methods. They provide practical information and guidelines for building solutions.

Over 120 building standards used for Building Regulations compliance are now available for free download.

See the free standards relating to Code Clause E2.

All standards, including the funded ones, can be accessed through the Standards New Zealand website.


These documents are provided for assistance. They are not intended as a means of establishing compliance with the Building Act or Building Regulations, and they do not have the same status accorded to Acceptable Solutions and Verification Methods under the Act.

Related Determinations

Determinations are made by MBIE on matters of doubt or dispute to do with building work. Rulings are legally binding in relation to each case. Circumstances in one case may differ to others.

Related building products

All products, systems and construction methods that have achieved CodeMark status will be listed here with their most up to date certificate.




This information is published by the Your home’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: