2026 Guide to Building a NatHERS 7-Star Home in Australia
- Smart SIPs
- Dec 31, 2025
- 7 min read
As of the latest National Construction Code (NCC) updates, every new home build in Australia is now required to hit a minimum 7-star NatHERS rating. For many, this sounds like a regulatory headache. But for those looking at the bigger picture, it is an opportunity to build a home that is vastly more comfortable, significantly cheaper to run, and future-proofed against rising electricity costs.
Whether you are just starting your research or you are deep in the design phase, this guide will show you how to navigate the 7-star requirement and why hitting the minimum might actually be undershooting your potential.
What Does a 7-Star Rating Actually Mean?
The Nationwide House Energy Rating Scheme (NatHERS) scores a home’s thermal performance on a scale of 0 to 10 stars. It measures how much energy is required to keep a home comfortable throughout the year.
0 Stars: The building envelope does nothing to help with temperature; it is freezing in winter and a furnace in summer.
6 Stars: The previous Australian standard (established in 2010).
7 Stars: Represents a 25% reduction in the energy required to heat and cool the home compared to 6 stars.
10 Stars: A home that stays comfortable year-round with virtually no mechanical heating or cooling required.
1. Passive Design Principles
Before you choose a single material, you must address Passive Design. This is the art of using the sun, wind, and shade to do the heavy lifting for you.
Orientation: Your living areas should ideally face North. This allows the low-angle winter sun to penetrate deep into the home while the high-angle summer sun is blocked by eaves.
Zoning: Use internal doors to zone your home. Closing off a hallway or a media room means you aren't paying to heat or cool a room no one is using.
Window Placement: Minimise large glass areas on the West (to avoid the brutal afternoon sun) and the South (where heat escapes in winter).
2. Thermal Bridging and Air Leakage
Most Australian homes are built with a timber or steel frame. While familiar, these systems have a hidden flaw known as Thermal Bridging.
In a traditional 90mm timber frame, up to 25% of the wall area is actually solid timber (studs, plates, and noggings). These timber pieces act as a "bridge" for heat. Even if you put high-quality insulation batts between the studs, heat still leaks through the studs themselves. In steel-framed homes, this effect is even more dramatic, as steel conducts heat far more efficiently than wood.
3. The Easy Way to Meet and Exceed 7-Stars: Smart SIPs
If you are struggling to reach 7 stars with traditional framing, it is usually because the "leaky" nature of a stick-frame home is holding you back. This is where Structural Insulated Panels (SIPs) have become the logical choice for energy efficiency in Australia.
What are SIPs?
SIPs are high-performance building panels consisting of an insulating foam core (we use Neopor® by BASF) sandwiched between two structural facings (like OSB).
They replace the traditional frame and insulation in one single, high-strength step.
How Smart SIPs Smash the 7-Star Barrier:
Continuous Insulation: Because the insulation is the core of the wall, there are no studs to create thermal bridges. Your insulation is a solid, unbroken blanket around your home.
Unbeatable Airtightness: Traditional homes are leaky, often testing at 10 to 15 Air Changes per Hour (ACH). Smart SIPs are so well-sealed that they frequently achieve 0.5 to 1.5 ACH, keeping your conditioned air inside.
Structural Superiority: Beyond efficiency, our panels are incredibly strong. The Neopor core acts as a "web" to the structural facings' "flange," similar to a steel I-beam. This allows them to handle extreme wind loads, with approvals for wind speeds up to 289 km/h.
4. Proof of SIPs Performance
Australian homeowners are already using Smart SIPs to blow past the 7-star minimum and reach "Super-Home" status.
The Canberra 9-Star Project
In one of Australia's toughest climates (bitterly cold winters and scorching summers), this project achieved a 9-star rating using Smart SIPs. By creating a super-insulated shell, the home requires almost zero mechanical heating even when Canberra temperatures drop below freezing.
The 8.4 Star All-Electric Home
This project proves that 7 stars is just the beginning. By utilising the airtightness of SIPs, this home reached 8.4 stars, allowing the owners to ditch gas entirely and run their comfortable lifestyle on a modest solar array.
The 8.3 Star Off-Grid Studio
Even small footprints benefit from SIPs. This off-grid studio achieved 8.3 stars, ensuring that the limited power available from a battery system is never wasted on inefficient heating or cooling.
Passive House Certification
For those seeking the ultimate in health and efficiency, Smart SIPs are the preferred choice for Passive House builds. A recent project using our system achieved the incredibly rigorous Passive House certification, which requires levels of airtightness and thermal control far beyond the standard NCC minimum.
5. Glazing
You can have the best walls in the world, but if your windows are poor, your rating will suffer. High-performance windows are the essential partner to an airtight SIPs shell.
Whether you are aiming for a Passive House build or a comfortable family home, pairing SIPs with thermally efficient windows ensures there are no weak links in your building envelope.
Double Glazing as a Minimum: Under new 7-star rules, single glazing is almost impossible to use for a pass.
Thermal Consistency: When working with us, we partner with you to ensure your windows support your design preferences while maximising long-term energy efficiency.
The SIPs Advantage: Because our walls are so efficient, you often have more budget in your NatHERS assessment to keep those large, beautiful windows you want without failing your rating.
6. Build for the Australian Environment: BAL and Wind Ratings
Building in Australia requires more than just energy efficiency; it requires resilience.
Bushfire Safety: We can engineer Smart SIPs to meet various Bushfire Attack Level (BAL) ratings, including BAL-40 and Flame Zone (FZ). By using our cSIPs (Cement Skin panels), you build a structural wall and fire-rated cladding in one action.
Wind Performance: Whether you are building in a high-wind zone or a cyclone-prone region, Smart SIPs are approved for winds up to 289 km/h. Our system is fully BCA compliant and independently tested to ensure your home stands strong.
7. The Financials: Cost vs. Savings
While a SIPs build may cost roughly 5% to 10% more in upfront materials than a traditional timber frame, the total project costs are often comparable due to reduced labour time (lock-up in days, not weeks).
The real savings, however, are found in the running costs. Homeowners in Smart SIPs houses typically see a 30% to 55% reduction in heating and cooling bills. In a 2026 energy market, this translates to thousands of dollars saved every year. Furthermore, the high star rating increases the resale value of your home as buyers increasingly prioritise energy efficiency.
8. The Whole-of-Home Energy Budget
New for the 2026 building landscape, the NCC includes a Whole-of-Home budget. This means your energy rater looks at your fixed appliances (hot water, heating, cooling, lighting) and calculates an annual energy spend.
By building a SIPs home that stays at a stable temperature naturally, you can install smaller, more efficient air conditioning units. This lowers your energy spend and makes it much easier to hit your targets with room to spare.
Building a NatHERS 7-star home: How to Get Started
Building to 7 stars should not be about adding more "stuff" to a bad design. It is about choosing a better building system from day one.
Engage an Energy Assessor Early: Don't wait until your plans are finished. Get a preliminary NatHERS rating while you can still make changes.
Prioritise the Envelope: Spend your budget on the walls, roof, and floor first. You can always upgrade a kitchen later, but you can never easily upgrade the insulation inside your walls.
Consider Smart SIPs: If you want a home that is fast to build, incredibly quiet, and guaranteed to exceed 7 stars, our system is the most logical choice for the modern Australian climate.
Ready to exceed 7 stars?
Whether you are building an off-grid studio or a large family home, our team can help you specify the right system to make compliance easy.
Frequently Asked Questions about 7-Star Compliance
How much does it cost to upgrade a 6-star design to 7 stars?
With traditional timber framing, upgrading often requires expensive additions like thicker wall cavities, premium insulation batts, and high-spec double glazing, which can add $15,000–$40,000 to a standard build. By choosing Smart SIPs from the start, you hit 7 stars (and often 8 or 9) through the structural system itself, often making it more cost-effective than "fixing" a traditional frame.
Can I use Smart SIPs for just the roof or just the walls?
Yes. While a full Smart SIPs envelope provides the best thermal performance and airtightness, our panels are modular. Many homeowners choose to use SIPs for the roof, where the most heat gain and loss occurs, while using traditional framing or SIPs for the walls to meet their specific budget and design goals.
Do 7-star homes require special air conditioning or heating?
Actually, they require less. Because a 7-star (or higher) SIPs home is so well-insulated and airtight, the "thermal load" is much lower. This means you can often install smaller, less expensive heating and cooling units. This is a key part of the new "Whole-of-Home" energy budget required by the NCC.
Are Smart SIPs better than traditional "stick" framing for energy ratings?
Significantly. Traditional framing suffers from "thermal bridging," where heat escapes through the timber studs. Smart SIPs provide a continuous layer of high-performance Neopor® insulation with no thermal breaks. This allows SIPs to achieve much higher R-values in a thinner wall profile compared to timber.
How does airtightness affect my NatHERS rating?
Airtightness is the "secret ingredient" to high ratings. Even a well-insulated home will perform poorly if it is "leaky." Smart SIPs create an airtight seal that prevents conditioned air from escaping, which is why they are a preferred choice for achieving Passive House standards and high star ratings in extreme Australian climates.
Will a 7-star home stay cool in an Australian summer?
Yes. While much of the focus is on winter warmth, the high R-values and reflective graphite-infused Neopor® core in Smart SIPs are incredibly effective at reflecting radiant heat. This keeps the interior of the home significantly cooler than the outside temperature, even during 40°C+ heatwaves.