Why Coating Standards Matter
Coating standards exist to ensure consistency, performance, and safety across building and industrial projects in New Zealand and Australia.
Without agreed standards, there is no common benchmark for what constitutes a quality coating job. The result can be variable quality from one applicator to the next, premature coating failure, and disputes over who is responsible when things go wrong. Coating standards solve this by setting clear, measurable performance requirements that everyone involved in a project — from the architect who specifies the finish, to the fabricator, to the coating applicator — can work to.
Standards are used by architects, engineers, specifiers, contractors, and asset owners across the building and infrastructure sectors. They protect building owners and end users by ensuring that coatings applied to structural steel, architectural aluminium, and other metal components will perform as intended over the design life of the structure.
In New Zealand and Australia, the two most commonly referenced coating standards are AS/NZS 3715 (which covers powder coating for architectural purposes) and AS/NZS 2312 (which provides guidance on protecting structural steel from atmospheric corrosion). Understanding what these standards cover, and when they apply, helps ensure that your project is specified and finished to the right level.
AS/NZS 3715 — Powder Coating of Metal Products for Architectural Purposes
AS/NZS 3715 is the key standard governing architectural powder coating in Australia and New Zealand.
AS/NZS 3715 sets out the performance requirements for thermoset powder coatings applied to metal products intended for architectural use. It covers both aluminium and steel substrates and is the standard most commonly referenced on commercial building projects, government facilities, and architectural fitouts where a specified level of coating performance is required.
The standard addresses a range of performance properties, including minimum film thickness, gloss retention after weathering, colour consistency across production runs, adhesion of the coating to the substrate, impact resistance, surface hardness, chemical resistance, and salt spray performance. These requirements ensure that powder coated architectural components — such as window frames, curtain wall mullions, facade panels, and balustrades — maintain their appearance and protective function over the building's service life.
Specifiers on commercial and government projects commonly call up AS/NZS 3715 in their project documentation to set a minimum performance benchmark. When a project specification references this standard, it means the coating applicator must demonstrate that their processes and materials meet the requirements set out in the standard. This gives architects, engineers, and building owners confidence that the finished coating will perform to a known and tested level.
AS/NZS 2312 — Guide to the Protection of Steel Against Exterior Atmospheric Corrosion
AS/NZS 2312 provides guidance on selecting appropriate protective coating systems for steel exposed to outdoor environments.
AS/NZS 2312 is a guide — rather than a strict compliance standard — that helps specifiers, engineers, and asset owners select appropriate protective coating systems for steel exposed to outdoor atmospheric conditions. It is the go-to reference for anyone specifying corrosion protection on structural steelwork in New Zealand and Australia.
One of the most important concepts in AS/NZS 2312 is the corrosivity category system. Environments are classified from C1 (very low — dry, heated interiors) through C2 (low — rural areas with low pollution), C3 (medium — urban and light industrial), C4 (high — industrial or coastal with moderate salt exposure), C5 (very high — aggressive industrial or marine with significant salt spray), and CX (extreme — offshore or direct immersion). Each category reflects the level of corrosive stress the steel will be exposed to, and the coating system must be selected accordingly.
In New Zealand, the environment varies significantly depending on location. A steel structure in an inland rural area might fall under C2, while the same structure located within a few hundred metres of the coast could be rated C4 or C5. The standard provides guidance on matching coating systems — including zinc-based systems, epoxy primers, and polyurethane topcoats — to the appropriate corrosivity category. Services such as zinc arc wire spray and multi-coat wet spray painting systems align directly with the protective coating systems described in this guide, making it a practical reference for specifying the right level of protection for any project.
Other Relevant Standards
Depending on your project, additional standards may apply to surface preparation, coating thickness, or specific applications.
ISO 8501 defines visual standards for surface cleanliness achieved by abrasive blast cleaning. It uses a grading system — Sa 1 (light blast), Sa 2 (thorough blast), Sa 2.5 (very thorough blast, near-white metal), and Sa 3 (blast to visually clean steel) — that is universally referenced in coating specifications. Sa 2.5 is the most commonly specified grade for structural steel corrosion protection work, as it provides the level of surface cleanliness needed for high-performance coating systems to adhere properly.
AS/NZS 4506 covers thermosetting powder coatings and sets out requirements for the powder materials themselves, including their chemical and physical properties. This standard is relevant when specifiers need to confirm that the powder coating product being used meets defined performance criteria, and it is sometimes referenced alongside AS/NZS 3715 on architectural projects.
Qualcoat is a European quality label for architectural powder coating that is sometimes referenced in New Zealand specifications, particularly on projects with international design teams or where a high level of quality assurance is required. The ACFA (Australasian Certification for Finishers of Aluminium) scheme provides a regional framework for certifying powder coating applicators who work on architectural aluminium. Participation in these schemes involves regular audits, testing, and compliance with specified process and performance requirements. While not every project will reference these additional standards, being aware of them helps specifiers and contractors understand the broader quality landscape for architectural coating work.
Who Needs to Comply?
Coating standards are typically specified by architects, engineers, or project managers on commercial and infrastructure projects.
Coating standards are most commonly specified on commercial construction projects — curtain wall systems, facade cladding, aluminium window and door joinery, structural steel, and architectural metalwork. On government and public infrastructure projects, compliance with relevant standards is often a mandatory requirement of the contract documentation.
When a building consent or project specification explicitly calls up a coating standard, it means the contractor and every subcontractor involved in the coating process must demonstrate compliance. For the coating applicator, this typically means working to documented procedures, maintaining records of coating thickness and adhesion testing, and being able to provide evidence of compliance if asked.
The distinction is worth understanding: on commercial and architectural projects, compliance with a named standard is commonly expected and often contractually required. On smaller retail jobs, residential work, and DIY-scale projects, formal compliance with a specific standard is less commonly relevant — though the same quality principles still apply. When contractors and fabricators receive a project specification that calls up a coating standard, they pass that requirement through to their coating subcontractor, who becomes responsible for meeting it. If you are unsure whether your project requires compliance with a specific standard, it is worth checking with your specifier or contacting us to discuss.
How Coating Lab Meets Standards
Understanding and working to the relevant standards is part of how we deliver quality results for commercial and architectural projects.
Working to recognised standards is about more than ticking a box — it reflects a commitment to consistent, measurable quality. Internal quality control processes such as checking film thickness with calibrated gauges, testing adhesion, and verifying gloss levels are practical steps that ensure the finished product meets the required performance criteria.
Specifiers and contractors who require standards-compliant coating should discuss their project requirements with the Coating Lab team at the quotation stage. This allows us to confirm the applicable standard, agree on the required performance criteria, and plan the work accordingly. If your project requires documentation such as test reports or compliance records, raise this early so it can be factored into the scope of work.
If you have a project that references AS/NZS 3715, AS/NZS 2312, or any other coating standard and you want to discuss how we can meet those requirements, get in touch with our team.
Specifying Coating Standards on Your Project
If you're a specifier, architect, or engineer including powder coating in your project documentation, here's how to approach the specification.
A well-written coating specification removes ambiguity and sets clear expectations for everyone involved. At a minimum, a good powder coating specification should include a reference to the applicable standard (such as AS/NZS 3715), the performance category or exposure rating, the colour specified by RAL number or manufacturer reference, the required gloss level, the finish type (smooth, textured, metallic, etc.), and the acceptance criteria for the finished work.
On complex commercial projects, a pre-job meeting between the specifier, the contractor, and the coating applicator is a valuable step. It provides an opportunity to align on expectations, clarify any ambiguities in the specification, and agree on the sample and approval process. Having a signed-off colour and finish sample before a full production run begins can prevent costly disputes and rework later in the project.
If you are working on a project that requires coating to a named standard and you would like to discuss the specification, the process, or any documentation requirements, submit an enquiry or call the team directly. The earlier we are involved in the conversation, the better the outcome for everyone on the project.
Frequently Asked Questions
AS/NZS 3715 is the joint Australian and New Zealand standard that sets performance requirements for thermoset powder coatings applied to metal products for architectural use. It covers properties such as film thickness, adhesion, gloss retention, colour consistency, impact resistance, and salt spray performance. It is commonly called up by architects, engineers, and specifiers on commercial building projects to ensure that powder coated components meet a defined quality benchmark.
It depends on the type of project. On commercial construction, government, and infrastructure projects, coating standards are commonly specified in the project documentation and compliance may be contractually required. On smaller residential or private projects, a formal standard is less commonly referenced, though the same principles of good practice still apply. Check your project specification or building consent documentation — if a standard is named, it needs to be followed. If you are unsure, contact the Coating Lab team and we can help you work out what is required.
Coating Lab is committed to delivering work that meets the requirements of relevant NZ and Australian coating standards. We use calibrated equipment for quality control checks including film thickness, adhesion, and gloss measurement. If your project references a specific standard, discuss it with our team at the quotation stage so we can confirm the scope and any documentation requirements. Contact us to talk through your project needs.
AS/NZS 3715 deals specifically with the performance of powder coatings applied to metal products for architectural purposes — it focuses on the quality and durability of the powder coat finish itself. AS/NZS 2312 is a broader guide to selecting protective coating systems for structural steel exposed to outdoor atmospheric corrosion — it covers the full range of coating options (including zinc-based systems, epoxy primers, and multi-coat paint systems) and helps match the right system to the corrosivity of the environment. The two standards serve different purposes and it is not uncommon for both to be referenced on the same project where both architectural powder coating and structural steel protection are involved.