NCC 2025 vs. NCC 2022: Which Building Code Applies to Your WA Project?

In the world of Western Australian construction, timing is everything. Whether you are a builder managing a pipeline of custom homes or a homeowner planning a major renovation, the code under which your building permit is assessed dictates your budget, your materials, and your liability.

The landscape shifted significantly on 1 May 2025. While the industry has been buzzing with talk about "NCC 2025," the reality on the ground is that NCC 2022 Amendment 1 is the current operational baseline for projects today.

At Shoal Bay Projects, we specialize in construction advisory in Australia, helping clients navigate the complex intersection of national standards and specific Western Australian variations. Understanding which code applies: and how the WA-specific tweaks affect your build: is the difference between a compliant project and a costly rectification nightmare.

The Compliance Timeline: 2022 Amdt 1 vs. 2025

The Australian Building Codes Board (ABCB) released NCC 2022 Amendment 1 to address specific industry pressures and minor errors while the 2025 edition was finalized. In WA, this amendment took full effect in May 2025.

While NCC 2025 is now available (having been published in early 2026), its mandatory adoption for most building permits in WA doesn't hit until 1 May 2027. This means we are currently in a "Goldilocks zone" where NCC 2022 Amendment 1 (including its specific WA variations) is the standard you must master.

For those of you looking to stay ahead of the curve, The Hive is where we break down these shifts in real-time. Welcome to the community hub where we turn technical compliance into project-saving strategy.

1. Gutters and Downpipes: The AS/NZS 3500.3:2021 Shift

One of the most critical updates in NCC 2022 Amendment 1 for WA builders relates to roof drainage. Historically, achieving the required fall in eaves gutters has been a point of friction on-site.

The WA Variation:
Industry Bulletin 168 clarifies that under the Housing Provisions (HP) Part 7.4, WA builders now have more flexibility. You can now use AS/NZS 3500.3:2021 (Plumbing and drainage – Stormwater drainage) in conjunction with the NCC.

• Fall Requirements: This variation allows for eaves gutters with a fall less than 1:500, provided the design aligns with AS/NZS 3500.3.
• Vertical Downpipes: If you are utilizing this solution, downpipes must be fitted vertically to the sole of the gutter.
• Rectangular Solutions: A specific WA variation to Schedule 2 now provides a clear compliance pathway for 95mm x 45mm rectangular downpipes, a common choice in Perth’s residential market.

2. Windows in Masonry: Rethinking the 10mm Head Gap

If you’ve spent any time on a WA building site, you know that double-brick construction (masonry) is our bread and butter. The national standard for window installation (HP Part 8.2) requires a minimum 10mm gap between the window head and the nearest loadbearing element.

However, the WA variation in Amendment 1 recognizes our unique building practices. The required gap can now be less than 10mm in masonry construction, provided that the gap is sufficient to prevent the transfer of structural loads to the window frame.

The Strategic Takeaway:
Document this. If you are reducing that gap, ensure your site supervisor and building surveyor are aligned on how "structural load transfer" is being prevented. This is where building consultancy services become vital: we provide the technical oversight to ensure these variations don't lead to cracked glass or jammed sashes later in the warranty period.

3. Energy Efficiency: Concessions for Extensions

Energy efficiency is often the most expensive part of a modern building contract. Under NCC 2022 Amendment 1, WA has introduced three specific variations that provide much-needed relief for homeowners undertaking renovations or extensions.

The "Time Travel" Concession (Part H6)

For alterations and extensions to existing buildings, WA Volume Two Part H6 allows for the continued application of NCC 2019 Amendment 1 energy efficiency requirements. This is a massive win for homeowners, as it avoids the "all-or-nothing" upgrade trap where a small extension triggers a mandatory 7-star upgrade for the entire existing dwelling.

Climate Zone 6 Alignment

WA variations now allow Climate Zone 6 (parts of the South West) to be considered as Climate Zone 5 for the purposes of building fabric and external glazing. This simplifies window selection and insulation requirements for many regional builds.

Suspended Floor Insulation

Part 13.2.7 has been varied to specify exactly what insulation is required for suspended floors in climate zones 4 and 5 (covering much of the Perth metro and coastal areas). This clarifies the requirements for upper-story additions or "stilt" homes that project beyond the ground floor footprint.

4. Construction Compliance and Risk Management

Navigating the NCC is no longer just about following a set of rules; it’s about managing risk. At Shoal Bay Projects, we operate at the advisory level to ensure your project stays aligned with both contractual and regulatory requirements.

Why Advisory Matters Now:

• Contractual Alignment: Many standard-form contracts haven't yet caught up with the specific WA variations in Amendment 1.
• Quality Expectations: Performance solutions are becoming more common. If your builder is using a performance solution instead of a Deemed-to-Satisfy (DTS) solution, you need an independent eye to verify the evidence of suitability.
• Forensic Precision: We use a 3D, forensic approach to interpret compliance. We don't just look at the plans; we look at the physics of how a building will perform over 20 years.

Summary: Check, Specify, Document

If you are starting a project in WA today, your "NCC 2022 Amendment 1 Checklist" should look like this:

1. Check the Permit Date: Ensure you are being assessed under the correct code.
2. Specify the Standards: If you're using AS/NZS 3500.3:2021 for gutters, make sure it’s in the plumbing schedule.
3. Document Windows: Confirm the masonry window head clearance with your installer.
4. Leverage Concessions: If you're extending, use the NCC 2019 energy efficiency pathways to save on costs.

The transition to NCC 2025 will eventually tighten the screws on energy efficiency and condensation management even further. Preparing your workflows now under the 2022 Amendment 1 variations is the best way to future-proof your business or your home.

For a deeper dive into how these rules apply to your specific site, check out our Executive Services Overview or join the conversation at Shoal Bay Projects. We are here to ensure your build is more than just a structure: it's a compliant, high-performing asset.

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