This standard provides methods and details that are used to design many New Zealand timber-framed houses and small buildings.

NZS 3604 forms part of a compliance document for design of timber framed buildings because it is sited in the acceptable solution B1/AS1. 

It is not commonly known that B1/AS1 section 3.0 lists NZS 3604 as the acceptable solution for timber construction, but states that it must be subject to a number of modifications, which it explains in detail.

The first of these modifications was specified in August 2011 following the Canterbury earthquakes when it was found that some of the slab and foundation details had not performed well. Further modifications have been added including significant changes to timber deck design in 2017.

The most recent amendment (19) excluded liquefaction and lateral spread from the definition of good ground and provided new slab-on-ground solutions for ground subject to expansive soils. This document came into effect on the 28 November 2019 and the previous version ceased to have effect on the 31 March 2020, except for the definition of good ground for NZS 3604, which will stay in effect until 29 November 2021.

To become familiar with the modifications to NZS 3604 or to print or view a copy of this standard visit the Standards New Zealand website.