Building control documents explained

The building control system has many documents, so it can be hard to know where to find information. This new series starts by explaining the hierarchy of the key documents and the importance of keeping them updated

The hierarchy of documents for New Zealand building controls is:

• Building Act 2004 and subsequent amendments (the latest being 2013).
• New Zealand Building Code (produced under the Building Regulations).
• Acceptable Solutions and Verification Methods, which may cite appropriate standards (national and international) as a means of compliance.

A good resource that explains the New Zealand Building Control system (NZBC) is BRANZ’s Building Basics: Building Controls.

The Building Act

The Building Act provides the framework for the NZBC. For details, see www.dbh.govt.nz/ba-about-the-building-act.

Building Regulations

These contain the rules for building consent authorities, LBPs, prescribed forms and applicable penalties. They also list specified systems, define ‘change of use’ and ‘moderate earthquake’, and set out the rate of any levies and fees for determinations.

Regulations related to Building Code clauses were initiated by the Building Regulations 1992. This has been since revoked, except for Regulation 3 and Schedule 1:

Regulation 3 covers the performance criteria specified in the Building Code for the classified use of that building.

Schedule 1 of the Building Regulations 1992 covers building uses, interpretation and importance levels and then covers objectives, and functional and performance requirements.

For more on the Building Regulations, see page 6 of the New Zealand Building Code Handbook, available at www.dbh.govt.nz/compliance-documents#handbooks.

New Zealand Building Code

The performance-based NZBC has 37 clauses and three preliminary clauses. These set out the functional requirements and performance criteria that the Building Act requires all buildings to meet. They do not prescribe how the work should be done.

To comply with the Building Code, building work has to satisfy the requirements set out in each clause. Building Code clauses offer a Verification Method and/or an Acceptable Solution; most have both.

Pathways to compliance in line with the Building Code include:

• Verification Methods.
• Acceptable Solutions.
• Determinations.
• Product certification (where the product use is within the scope of the product certification).

The current scheme is known as CodeMark.

Alternative Solutions

Sometimes a different building solution is needed. Any detail or method outside the Acceptable Solutions or Verification Methods needs to be consented as Alternative Solutions.

Alternative solutions must be presented to the BCA with supporting evidence. Once consented, it becomes an Alternative Solution. Supporting evidence may be:

• A satisfactory history of use in a comparable situation.
• A comparison to an acceptable solution.
• A previously accepted comparable alternative solution.
• Independently assessed performance, such as a BRANZ appraisal.
• The subject of an expert opinion.
• Favourable test results relevant to the proposed use.

A good resource that explains all of this is BRANZ’s Building Basics – Building Code Compliance.

 

“Alternative solutions must be presented to the BCA with supporting evidence

 

Always use the latest version!

All 37 Building Code clauses are available free from www.dbh.govt.nz/compliance-documents. It’s good to practice to check you are using the latest version.

Standard format for clauses

Each Building Code clause has a similar structure. As an example, let’s look at Building Code clause B1 Structure that covers Acceptable Solutions and Verification Methods for B1 Structure. In order, it contains:

• Document status with the history of all document alterations.
• Relevant extracts from the first schedule of the building regulations 1992 with:
  –  objectives
  –  functional requirements
  –  performance requirements
• Contents.
• References indicating the versions of standards and other documents that apply to the Acceptable Solutions, Verification Methods, and where in the building code clause they are quoted.
• Definitions.
• Verification Methods that provide a means for the design of structures to meet the performance requirements of the Building Code – for example, B1/VM1 covers verification methods for general construction, referencing relevant standards.

Acceptable solutions that provide either a specific deemed-to-comply solution or references standards that, if used as required, will meet the performance requirements of the building code – for example, B1/AS3 includes specific solutions for small chimneys.

Code may change standards

Cited standards can be modified by clauses within Acceptable Solutions and Verification Methods.

It’s always a good idea to check the relevant Code clauses to see if they are modifying the referenced standard, or have referenced a later version of the standard.

For example, B1/AS1 references NZS 3604:2011 as an Acceptable Solution for timber-framed buildings, but B1/AS1 page 23A, clause 3.1, says: ‘NZS 3604 subject to the following modifications’. The listed modifications need to be made to use the standard.

Standards modified by B1 Amendment 12 in February 2014 were AS/NZS 1170, NZS 4211, NZS 4223, NZS 4229 and AS/NZS 4600.

Standards modified by B1 Amendment 11 in August 2011 were AS/NZS 1170, AS/NZS 1664.1, NZS 4211, NZS 4219, NZS 4229, NZS 3603, NZS 3604, NZS 4229, NZS 4223, NZS 4297 and AS/NZS 4600.

When a standard is updated by its publishers, the new version is not automatically a means of compliance. It must be referenced anew by MBIE in the Building Code clause.

 

“To comply with the Building Code, building work has to satisfy the requirements set out in each clause. Building Code clauses offer a Verification Method and/or an Acceptable Solution; most have both

 

Keep your standards current

A good method to keep your standards up to date is to look at the relevant Acceptable Solutions and Verification Method clauses, for example, B1/AS1 Structure when using NZS 3604:2011.

Check if amendments have been made to the standard, or if a later version is referenced. Print any amendments to the standard and cut and paste over the original clauses to avoid confusion.

The side columns in the Building Code clauses always have the amendment number and date modified, so the most recent changes can be tracked.

If a later version of the standard has been referenced without amendment, use the later version of the standard.