Mar 2011 - New Minimum Standard for Residential Foundations

30 March 2011

The Christchurch City Council has issued a notice with regards to a new minimum standard for residential foundations following the September and February earthquakes in Canterbury.

Residential Foundations: Indications are that the foundation designs provided in the Department of Building and Housing's publication 'Guidance on House Repairs and Reconstruction following the Canterbury Earthquake' will be adopted for Christchurch and become the new minimum standard.

Accordingly, for one and two storey buildings it is strongly recommended that their foundation designs are based (as a minimum) on the options provided in this publication.  Click here to download a copy. 

This guidance document is sanctioned by both the Department of Building and Housing and the Insurance Council of New Zealand for use whilst earthquake requirements of current cited compliance standards are reviewed.

Seismic Bracing: As a minimum it is strongly recommended that you use the next higher earthquake zone out of NZS 3604 (Zone A 1999 Version, or Zone 3 for the 2011 version).  If the design is to NZS 1170.5, then apply the same seismic factors as for Wellington.

The adoption of the above loads and designs is not yet compulsory, however, is strongly recommended in order to protect your building to likely future standards.