An introduction to weathertightness design principles

All content related to E2 External moisture

About this document

  • Published on 18 August 2006
  • Of interest to Building owners, Builders, Designers, Quantity surveyors, Architects, Roofers,
  • ISBN: 0-478-29731-9 (Print) / 0-478-29732-7 (Online)
  • 1st edition


Principles of weathertightness design, including a valuable summary of critical performance components for effective cladding systems.

Core principles for the construction of buildings that are weathertight. This guidance provides a clear explanation of the basis on which good weathertight buildings can be constructed in New Zealand. It is not intended as a prescriptive ‘how to’ guide, rather it sets out principles that act as a checklist for performance-based designs outside the Acceptable Solutions and Verification Method for Building Code Clause E2.

Helps understand the principles behind constructing weathertight buildings and provides information on where to seek further details. It provides understanding and knowledge for designing, evaluating or building specific ‘performance-based’ solutions (alternative solutions).

The information in the guide is divided into two broad sections:

Part A – Principles of weathertightness

  • This section introduces the primary physical influences affecting joints and claddings that effective cladding systems must be designed and built to resist.

Part B – Weathertightness principles applied

  • This section builds on the weathertightness principle of Part A to explain how some common cladding types can manage physical forces in ways that provide effective weatherresisting systems.

Knowledge of the principles of weathertightness is considered essential for all designers and builders of small-to medium-sized buildings, for building officials, educators and those with a general interest in weathertightness such as insurers, developers and funders of building projects.

All guidance documents related to E2 External moisture

This information is published by the Ministry of Business, Innovation and Employment’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: