Consultation on proposed amendment to the Compliance Document for Clause B1 Structure

The Department of Building and Housing is seeking feedback on proposed changes to Acceptable Solution B1/AS1 General, as contained in the Compliance Document for Clause B1 Structure.

This Acceptable Solution provides approved means of construction that comply with the Building Code, largely by citing New Zealand Standards. In this case the emphasis is on timber-framed construction for housing. The relevant Standard is NZS 3604: 1999 Timber Framed Buildings.

The proposal is to cite Amendment 2 to NZS 3604 in B1/AS1. A draft of the amendment has been prepared by Standards New Zealand (SNZ). The Department and SNZ jointly are seeking public comment on its proposals.

Amendment 2 is a direct consequence of Amendment 4 to NZS 3603: 1993 Timber Structures Standard on which, earlier this year, the Department sought public comment on its proposal to cite in the Clause B1 Compliance Document.

Amendment 4 introduces and provides the engineering properties of verified timber (ie, the new VSG and MSG grades) and down-rates the properties of unverified visually graded timber (No. 1 framing). Amendment 2 amends the tables and design information in NZS 3604 to account for the new VSG and MSG grades and the revised properties of No. 1 framing.

The Department has not yet made a decision on whether Amendment 4 of NZS 3603 will be cited. Submissions received on Amendment 4 were mixed, with some commentators concerned about the effect on their business and the extent of the then-unknown consequential changes to NZS 3604.

As NZS 3603 and NZS 3604 are linked, it is the Department's intention not to make any decision in respect of citing either Amendment 4 to NZS 3603 or Amendment 2 to NZS 3604 until such time as it has considered the comment received on the latter. It is likely that any citations of the amendments in the Clause B1 Compliance Document would occur at the same time.

The closing date for submitting comments on the proposed changes is 17 March 2006.

Comments should preferably be sent to SNZ, although they can be sent direct to the Department if commentators wish. A PDF file of the consultation document and Amendment 2 to NZS 3604 can be obtained from www.standards.co.nz (click on the 'drafts for comment' tab) or a hard copy can be obtained by calling SNZ on 0800 782 632 (there is a cost associated with acquiring the hard copy of this draft).

The consultation document and Amendment 2 can also be downloaded from the Department's website www.dbh.govt.nz, or a hard copy can be obtained by calling the Department on 0800 242 243.