If you're researching NCC 2025 windows requirements, Australia's building regulations are about to change — and your NCC 2025 windows decision is more important than ever.
The National Construction Code (NCC) 2025 was published for preview on 1 February 2026, with states and territories able to adopt the new rules from 1 May 2026. While the headline changes focus on condensation management, ventilated wall cavities, and commercial energy efficiency, the flow-on effect for residential windows is significant.
This guide breaks down exactly what's changing under NCC 2025 windows and glazing standards, what's not changing, and what Melbourne homeowners should do right now.
The NCC 2025 introduces mandatory ventilated wall cavities and updated condensation management provisions for Climate Zones 6-8, including Melbourne. Residential energy efficiency rules (the 7-star NatHERS minimum) were deferred, meaning current standards remain — but further tightening is expected. NCC 2025 windows that use uPVC double glazing with Low-E glass and argon fill already exceed every current and foreseeable requirement, with U-values as low as 1.6 W/m2K and internal glass temperatures of 16-18 degrees C on winter mornings. Acting before May 2026 adoption locks in current pricing and avoids potential approval delays.
The National Construction Code (NCC) sets the minimum requirements for the design and construction of buildings across Australia. It's updated periodically to address emerging issues in building performance, safety, and quality.
The NCC 2025 edition introduces targeted updates across several areas:
The Australian Building Codes Board (ABCB) published the preview so practitioners can prepare ahead of potential adoption from May 2026.
The NCC 2025 is the latest edition of Australia's National Construction Code, published for preview on 1 February 2026. States and territories can adopt it from 1 May 2026. It introduces mandatory ventilated wall cavities, updated condensation management provisions, and commercial energy efficiency changes. Residential energy efficiency rules were deferred and remain unchanged from NCC 2022 Amendment 2.
Over the past decade, Australian homes have become better sealed and insulated in pursuit of energy efficiency. While that's been excellent for reducing heating and cooling costs, it has created an unintended consequence: moisture has nowhere to go.
When warm, humid indoor air meets cold surfaces — particularly windows and wall cavities — condensation forms on the inside of windows, within wall cavities, and in roof spaces. Left unchecked, this leads to:
The NCC 2025 condensation provisions are a direct, evidence-based response to this problem. And your windows play a critical role in the solution. Choosing the right NCC 2025 windows can protect your home for decades.
| Change | Status in NCC 2025 | Impact on Windows |
|---|---|---|
| Ventilated wall cavities (Zones 6-8) | Mandatory | Window installation detailing must integrate with new cavity systems |
| Roof space ventilation (Zones 4-8) | Mandatory | Indirect — improved whole-of-home moisture management |
| Condensation management provisions | Updated | High-performance glazing reduces condensation risk on glass surfaces |
| Commercial energy efficiency (Section J) | Updated | Commercial window specifications affected |
| Residential energy efficiency (7-star NatHERS) | Deferred — no change | Current requirements remain — but future tightening is expected |
| EV charging provisions | Not included | No impact on windows |
The critical detail: residential energy efficiency changes were deferred. The proposed upgrades to Volume Two Part H6 and Housing Provisions Part 13 will not proceed in NCC 2025. The existing NCC 2022 Amendment 2 requirements — including the 7-star NatHERS minimum — remain.
This creates a window of opportunity (no pun intended). The current standards are here to stay for now, but further tightening is widely expected in the next code cycle. Upgrading your NCC 2025 windows today means you're already compliant — and likely ahead of whatever comes next.
No. The proposed residential energy efficiency upgrades were deferred from NCC 2025. The current NCC 2022 Amendment 2 requirements remain in force, including the 7-star NatHERS minimum for new homes. However, condensation management and ventilation provisions have been updated, and these directly affect how NCC 2025 windows integrate with the building envelope.
Melbourne predominantly falls within Climate Zone 7 (cool temperate), with some outer areas touching Zone 6. Both zones are squarely within the scope of the NCC 2025 changes.
Here's what that means in practice:
Direct-fix cladding — where cladding is fixed straight to the wall frame — will generally no longer be permitted in Zones 6, 7 and 8. Builders must include a continuous drained and ventilated cavity between the cladding and wall wrap.
For homeowners, this means window installations must integrate properly with the new cavity system. Correct flashing, drainage, and sealing around window openings becomes even more important to prevent moisture bridging.
The updated condensation provisions reinforce the importance of controlling moisture at every point in the building envelope — and windows are often the weakest link.
Single-glazed windows and older aluminium frames are the most common sites for visible condensation. The colder the glass surface, the more likely moisture will form. This is where your NCC 2025 windows glazing choice makes a measurable difference.
Yes. Melbourne sits within Climate Zone 7, which is directly affected by the NCC 2025 mandatory ventilated wall cavity and condensation management provisions. Both new builds and major renovations that trigger compliance will need to meet the updated requirements once Victoria adopts the code.
Windows are the thinnest, most thermally conductive part of any home's building envelope. In Melbourne's climate, where winter mornings regularly drop below 5 degrees C while indoor heating maintains 20 degrees C+, the temperature differential across a window can exceed 15 degrees.
With a single-glazed aluminium window, the internal glass temperature can drop low enough to hit dew point — and condensation forms. With a properly specified uPVC double glazed window, the internal pane stays significantly warmer, dramatically reducing condensation risk.
| Window Type | Internal Glass Temp (typical winter morning) | Condensation Risk | NCC 2025 Alignment |
|---|---|---|---|
| Single glazed aluminium | ~8-10 degrees C | High — frequently below dew point | Poor — does not support condensation management goals |
| Double glazed aluminium (non-thermal break) | ~12-14 degrees C | Moderate — frame remains a cold bridge | Marginal — frame conductivity undermines glazing gains |
| Double glazed aluminium (thermal break) | ~14-16 degrees C | Reduced — depends on break quality | Good — if thermal break is high quality |
| uPVC double glazed (argon + Low-E) | ~16-18 degrees C | ✓ Low — typically well above dew point | ✓ Excellent — exceeds current and foreseeable requirements |
Note: Temperatures are indicative based on typical Melbourne winter conditions (external ~4 degrees C, internal ~21 degrees C, moderate humidity). Actual results vary with specific glass specification, frame system, orientation, and ventilation.
The NCC 2025 changes put a spotlight on thermal performance and condensation control. So how do the two most popular frame materials stack up as NCC 2025 windows options?
| Feature | uPVC Double Glazed | Aluminium Double Glazed |
|---|---|---|
| Thermal conductivity (frame) | ~0.16 W/mK — excellent insulator | ~160 W/mK — 1,000x more conductive (thermal break reduces this) |
| Condensation on frames | Rare — frame stays warm | Common — especially without thermal break |
| 7-star NatHERS compliance | Meets or exceeds | Depends on thermal break quality and glazing spec |
| NCC 2025 condensation alignment | Excellent | Variable — depends on system |
| Maintenance | Minimal — won't rot, corrode, or need painting | Low — but may need seal replacement over time |
| Noise reduction | High — multi-chamber profiles absorb vibration | Moderate — rigid frame transmits more sound |
| Cost (typical Melbourne project) | Competitive — especially for whole-home replacements | Variable — high-quality thermally broken systems can cost more |
Both systems can deliver excellent results when properly specified and installed. But for homeowners specifically concerned about condensation, energy efficiency, and long-term maintenance, uPVC consistently offers the best all-round performance — and that advantage becomes more pronounced under NCC 2025.
For a deeper comparison, see our guide: uPVC vs Aluminium Double Glazed Windows in Melbourne.
Yes, in most cases. uPVC frames have a thermal conductivity of approximately 0.16 W/mK, compared to around 160 W/mK for aluminium — making aluminium roughly 1,000 times more conductive. This means uPVC frames stay warmer in winter, significantly reducing frame condensation and heat loss. While thermally broken aluminium narrows the gap, uPVC remains the superior thermal performer overall and aligns strongly with the NCC 2025 windows condensation management goals.
| WERS ID | Product | U-Value | SHGC |
|---|---|---|---|
| DEC-021-070 | Deceuninck Legend Art 70mm Tilt & Turn | 1.6 W/m2K | 0.32 |
| DEC-003-059 | Deceuninck uPVC Sliding System | 1.9 W/m2K | 0.40 |
Specifier tip: When comparing NCC 2025 windows, always request WERS-rated data from your supplier. U-values and SHGC vary significantly by frame profile, glass type, and gas fill. The figures above are verified ratings for the specific Windows Republic systems listed — not generic estimates.
Since NCC 2022, all new Australian homes must achieve a minimum 7-star NatHERS energy rating. While this primarily applies to new builds, it also sets the benchmark for renovations that trigger compliance — and it's the standard most Melbourne homeowners are now measuring against.
Windows are one of the most significant variables in achieving (or failing) a 7-star rating. Here's why:
With residential energy efficiency rules deferred in NCC 2025, the current 7-star target remains. But the writing is on the wall: future code cycles will almost certainly tighten requirements further. Investing in high-performance NCC 2025 windows now means you won't need to upgrade again when standards inevitably increase. For more on passive design and glazing performance, see the Australian Government's Your Home glazing guide.
To meet or exceed the 7-star NatHERS minimum, you need windows with low U-values (ideally below 2.0 W/m2K), appropriate SHGC for your orientation, and minimal air infiltration. uPVC double glazed windows with Low-E glass and argon gas fill are among the most effective options, with verified U-values as low as 1.6 W/m2K. Glass specification should be tailored to each elevation — your energy assessor and window supplier should work together to optimise the overall rating.
Whether you're building new, renovating, or simply tired of waking up to foggy windows every winter morning, the NCC 2025 timeline creates a clear decision point.
Condensation on the inside of windows is one of the most common complaints from Melbourne homeowners during winter. Understanding why it happens — and what actually fixes it — helps you make the right investment in NCC 2025 windows that perform.
Warm indoor air holds moisture. When that air contacts a cold surface (like a single-glazed window), the moisture condenses into water droplets. The colder the surface, the more condensation you get.
| Solution | Effectiveness | Notes |
|---|---|---|
| Open windows for ventilation | Moderate (temporary) | Helps reduce indoor humidity but lets cold air and noise in |
| Use exhaust fans (kitchen/bathroom) | Good | Essential — removes moisture at the source |
| Run a dehumidifier | Good (temporary) | Treats the symptom, not the cause |
| Wipe windows daily | Poor | Band-aid solution — moisture returns the next morning |
| Upgrade to double glazed uPVC windows | ✓ Excellent (permanent) | Keeps internal glass warm — prevents condensation from forming |
The most effective long-term solution is upgrading to windows that keep the internal glass surface above the dew point. Combined with good ventilation habits, uPVC double glazed windows with Low-E glass and argon fill virtually eliminate winter window condensation in Melbourne homes.
For more detail, see our guide: How to Deal With Condensation on Double Glazed Windows.
The most effective permanent solution is upgrading to uPVC double glazed windows with Low-E glass and argon gas fill. These keep the internal glass surface at 16-18 degrees C on a typical Melbourne winter morning — well above the dew point where condensation forms. Exhaust fans in kitchens and bathrooms help remove moisture at the source. Wiping windows and running dehumidifiers are temporary fixes that treat the symptom rather than the cause.
With NCC 2025 adoption possible from May 2026, there are practical reasons to act sooner rather than later:
Every NCC update over the past decade has moved in the same direction: better insulation, tighter sealing, lower energy consumption, and better moisture management. uPVC double glazed windows sit at the intersection of all four, making them the leading NCC 2025 windows solution.
Windows Republic manufactures uPVC double glazed windows locally in Cheltenham, Melbourne using European Deceuninck profiles, tailored specifically for Victorian conditions.
Explore our uPVC double glazed window range →
The NCC 2025 is a clear signal that Australian building standards are moving toward better moisture management, improved thermal performance, and higher-quality construction. For Melbourne homeowners, the most practical step you can take is upgrading to uPVC double glazed windows — they already exceed every current NCC 2025 windows requirement and position your home well ahead of whatever the next code cycle brings. Whether you're building, renovating, or simply want to eliminate winter condensation, acting before May 2026 adoption gives you the best combination of pricing, availability, and peace of mind.
The NCC 2025 preview was published on 1 February 2026. States and territories can consider adoption from 1 May 2026. Each jurisdiction decides its own adoption timeline — Victoria has not yet confirmed a specific date, but preparation now is strongly recommended.
No — the proposed residential energy efficiency changes were deferred. The current NCC 2022 Amendment 2 requirements, including the 7-star NatHERS minimum, remain in place. However, condensation management and ventilation requirements have been updated and will affect how NCC 2025 windows integrate with the broader building envelope.
The NCC applies to new construction and major renovations that trigger compliance. Existing homes are not required to retrofit. However, the condensation and moisture management problems the NCC 2025 addresses affect all homes — especially older properties with single glazing or non-thermally-broken aluminium windows.
Condensation forms when warm indoor air contacts a cold glass surface. Single-glazed and non-thermally-broken windows have low internal surface temperatures during winter, easily dropping below the dew point. Double glazed uPVC windows keep the internal pane significantly warmer, reducing or eliminating condensation.
Both can meet current NCC requirements when properly specified. However, uPVC naturally provides superior thermal insulation (approximately 1,000 times less conductive than aluminium), making it inherently better at preventing frame condensation and supporting whole-of-home energy efficiency. For Melbourne's Climate Zone 7, uPVC is the more straightforward path to NCC 2025 windows compliance.
The 7-star NatHERS rating is the minimum energy efficiency standard for new Australian homes under the current NCC. Windows are one of the largest variables — their U-value, SHGC, and air infiltration rates directly impact the overall rating. High-performance uPVC double glazed windows with Low-E coatings are among the most effective ways to meet or exceed this standard.
If you're planning a renovation or build, acting before adoption may avoid increased costs and approval delays. Even without a renovation trigger, upgrading from single glazing to uPVC double glazing delivers immediate benefits: less condensation, lower energy bills, reduced noise, and improved comfort — regardless of the code timeline.
Costs vary significantly based on window size, configuration, glass specification (Low-E, acoustic, tinted), number of openable sashes, and access for installation. The most reliable approach is to request a site measure and detailed quote with exact specifications confirmed in writing.
For Melbourne's Climate Zone 7, look for windows with a U-value below 2.0 W/m2K and an SHGC appropriate for the window's orientation. North-facing windows may benefit from a slightly higher SHGC to capture winter solar gain, while west-facing windows should have a lower SHGC to limit summer overheating. Always request WERS-rated data from your supplier — Windows Republic's Deceuninck Tilt & Turn system achieves a verified U-value of 1.6 W/m2K, making it one of the strongest-performing NCC 2025 windows options available in Victoria.
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