Postal ballot for revised NZS 3604 Timber framed buildings Standard reaches consensus

Issue 23 – December 2010

The postal ballot phase for the revised NZS 3604 Timber-framed buildings Standard has now concluded with technical committee members reaching consensus.

Standards New Zealand initiated the project to revise NZS 3604:1999 at the beginning of 2009. Feedback was sought from stakeholders on the main issues that needed to be addressed through a revision and this feedback informed the scope of the project.

The technical committee and the Leadership Group for the review of NZS 3604 approved a limited technical review of the Standard. This means that the committee focused on addressing only specific issues within the scope of the project. The committee has not completely rewritten the Standard. The review reflects the current and future needs of industry, changes in materials and industry practice, and the changes in related Standards since the last revision in 1999, including those Standards that set requirements for loadings.

Public comment on the draft revised NZS 3604 closed on 7 April 2010 and all comments were collated for the committee to consider, before a final version of the Standard was prepared for the committee to vote on during the postal ballot phase. Standards New Zealand extended the postal ballot period to give technical committee members working on the Canterbury earthquake more time to consider the postal ballot draft.

Standards New Zealand is now undertaking editorial and layout reviews of the revised edition of NZS 3604 prior to seeking Standards Council approval to publish.

The Department of Building and Housing has just commenced consulting on proposed changes to documents that many designers and builders use day-to-day, and is asking for submissions. This consultation includes the plans to cite the next version of the widely used NZS 3604 in B1/AS1. For more information see the article about the consultation below, Proposed changes to Building Code documents.

The revised edition of NZS 3604 is planned for publication in February 2011. Pre-orders for NZS 3604 can be made direct with Standards New Zealand, telephone 0800 782 632 during business hours or email

Consideration given to the Canterbury earthquake

Since the Canterbury earthquake on 4 September 2010 there has been much discussion on liquefiable soils and lateral spread across the sector and among the technical committee and leadership group working on the revised NZS 3604.

Some building consent authorities publish maps of earthquake hazards (including liquefaction) and these maps may be considered as part of any requirement for further assessment or specific engineering design.

There is currently not enough information and evidence-based research to decide if liquefaction should be addressed in the definition of 'good ground'. Several investigative and research projects have been initiated by the wider sector including the formation of a Strategic Advisory Group appointed by the Earthquake Commission to focus on the remedial work in Canterbury.

The Department of Building and Housing (DBH) is also working with other agencies on guidance information on liquefaction for remedial work in Canterbury. The intention is to publish the guidance information in December 2010. It is expected that this research, while focusing initially on the remedial work in Canterbury, will inform the wider building and construction sector as a whole.

DBH and Standards New Zealand have agreed to consider amendments to the revised edition of NZS 3604 or other documents when information and evidence about liquefaction and lateral spread is clear.

Published in building.