In New Zealand, durability is a compliance question and not only a quality one. Clause B2 of the New Zealand Building Code covers the durability of building elements, and B2/AS1 sits beneath that clause as an acceptable solution. If you are specifying materials for a building project, these are the requirements that set the standard your materials have to meet. What follows is a plain summary of what B2/AS1 covers and how compliance is demonstrated. It is a starting point, not a substitute for the clause itself.
What the B2/AS1 requirements are
The B2/AS1 requirements are part of the New Zealand Building Code and play a significant role in setting the standards for the durability of building elements. They are designed to ensure that building materials and components meet specific durability standards, so that the safety and integrity of buildings are maintained over time.
The detail sits in the Acceptable Solutions and Verification Methods for New Zealand Building Code Clause B2 Durability. That document is what to work from on a live project. The framing worth carrying into the rest of this article is that B2 is not asking whether a product is good in the abstract. It is asking whether a building element will still do its job later in the life of the building.
Durability periods
The B2/AS1 requirements specify minimum durability periods for building elements, which must meet certain standards with only normal maintenance. This ensures that the materials used in construction can withstand the test of time and environmental factors.
Two words there carry the weight. The first is 'minimum', which makes the period a floor rather than a target. The second is the qualifier 'with only normal maintenance': the standard is about the element holding its performance under ordinary care. That is why durability under B2 is expressed as a performance sustained over a period, rather than as a description of what a material is made of.
Ease of replacement and maintenance
The requirements also focus on how easy or hard building elements are to replace and maintain.
This is worth pausing on, because it means durability is not read off a material datasheet alone. Where an element sits in a building, and what it would take to get back to it, are part of the picture. An element that can be reached and swapped out sits in a different position from one that is buried, built over, or tied into the structure around it. The practical consequence for a project team is that access is worth thinking about at design stage, while it is still a choice. For how this applies to a particular element, work from the clause.
How compliance is demonstrated
Compliance with B2/AS1 can be demonstrated through laboratory tests, in-service history, and the comparable performance of similar building elements. This provides builders and developers with multiple ways to ensure their materials meet the necessary standards.
Each route relies on a different kind of evidence. Laboratory testing is the controlled path. In-service history rests on how the element has actually performed in real buildings over time. Comparable performance draws on similar elements with an established record. Which route is open to you depends on the element and on what evidence exists for it, so it is worth establishing early which one you are relying on rather than assuming a product is covered.
Why the B2/AS1 requirements matter
Adhering to the B2/AS1 requirements is essential for several reasons.
- Safety: ensuring that building materials meet durability standards helps maintain the safety of the structure over time.
- Longevity: using materials that comply with B2/AS1 helps ensure that buildings remain functional and aesthetically pleasing for longer periods.
- Regulatory compliance: meeting these requirements is necessary to comply with New Zealand's building regulations, avoiding potential legal and financial repercussions.
The three pull in the same direction. Durability is the mechanism by which a building stays safe and stays useful, and the regulation exists to make that outcome consistent across projects rather than left to the judgement of whoever specified the material.
Promax products and B2/AS1
Promax products are designed to meet the B2/AS1 requirements, so that they provide durability and compliance for your building projects. Our products are made from high-quality materials that adhere to the standards set by the New Zealand Building Code, so they can withstand environmental factors and maintain their integrity over time.
If you need the durability position for a specific Promax product on a specific project, ask us for it rather than inferring it from this page. The right answer depends on the product and on how it is installed. Our product documentation is the place to start, and our team can fill in the rest.
Getting it right on your project
Understanding and adhering to the B2/AS1 requirements is vital for any building project in New Zealand. Ensuring that your materials meet these standards is how you support the durability, safety and compliance of the work, and it is far cheaper to settle at specification stage than to revisit once the build is under way.
Contact us to learn more about how our products can help you meet the B2/AS1 requirements. If you are specifying tanks, our build sector page and specifier packs gather the product information in one place, and whether your tank needs a building consent answers the question that usually comes next. Our team is here to assist you every step of the way.