Standards New Zealand have recently released an updated standard for Timber Structures. There'll be a 12-month transition phase, during which you can use either NZS AS 1720.1:2022 or NZS 3603:1993 in your designs. After this period, the latter will be replaced with the new standard.

The primary differences between the standards are:

  • New or updated material properties (tension perpendicular to the grain, characteristic and mean densities, bearing strength).
  • The introduction of design methods for LVL (currently an Alternative Solution) and standard LVL grades.
  • Connection design based on a simplified (tabulated) method or the detailed method, allowing designers to control the connection behaviour by calculation yielding and brittle failure modes.
  • Rules for the seismic design of timber structures with the introduction of Potential Ductile Elements (PDE), Capacity Protected Elements (CPE) and overstrength.

The design of timber members and connections under fire has been removed from the new standard. This is now covered by AS NZS 1720.4.

View the standard