NatHERS Rating Guide: What It Means for Your Home Energy Use

If you’re building a new home, your NatHERS rating is one of the clearest indicators of how comfortable your house is likely to feel year-round and how hard your heater or air conditioner will need to work to keep it that way. NatHERS uses accredited software to simulate a home’s heating and cooling demand based on its design and local climate and converts this into a star rating out of 10. The higher the stars, the lower the predicted heating and cooling load, and the less energy you’ll need to stay comfortable.

What Does NatHERS Stand For? Full Meaning Explained

NatHERS stands for the Nationwide House Energy Rating Scheme. It assesses a home’s thermal performance (how well the building resists unwanted heat gain in summer and heat loss in winter). NatHERS is also used as a pathway to meet energy efficiency requirements under the National Construction Code (NCC).

How the NatHERS Star Rating System Works

The system runs on a 0–10 star scale, where 10 stars indicate very low heating and cooling demand for that climate. A NatHERS-accredited assessor inputs your specifications into accredited software, which models things like your orientation, window sizes, insulation levels, and shading. The software then estimates how much heating or cooling energy would be required to keep the home within a comfortable temperature band.

What Is a Good NatHERS Rating in Australia?

Under NCC 2022, the minimum thermal performance requirement for new homes increased from 6 to 7 stars (depending on state/territory timing and implementation), alongside a separate “Whole of Home” energy budget requirement. Here’s what that means:

• 6 stars: older baseline (still common in existing stock)
• 7 stars: current minimum benchmark in many places
• 8 stars: generally considered above average

7-Star vs 8-Star Homes: What’s the Difference?

A jump from 7 to 8 stars usually means:

• Insulation: higher R-values in key areas (roof/ceilings, external walls)
• Glazing: improved window performance (better U-values, better solar control)
• Shading & sealing: smarter eaves/external shading and reduced draughts

How NatHERS Affects Your Energy Bills

Because NatHERS focuses on heating and cooling demand, higher ratings mean lower running costs in those areas. Research suggests that moving from 6 to 7 stars can reduce heating and cooling energy use by roughly 20–25% (although figures vary by climate zone and design).

Factors That Influence Your Home’s Energy Rating

A few big levers make a real difference:

• Orientation: living areas positioned to catch winter sun (and avoid harsh western heat)
• Layout: grouping rooms and placing windows strategically (see our home designs for examples)
• Insulation: ceiling/wall upgrades that slow heat flow
• Glazing: window size, type, and placement
• Shading: eaves, pergolas, and external blinds that block summer sun
• Materials: thermal mass choices (where appropriate) and airtightness details

How to Improve NatHERS Rating When Building a New Home

For many volume home buyers, how to improve the NatHERS rating often comes down to:

• Upgrading key insulation zones (roof/ceiling is often the easiest ROI)
• Choosing better-performing glazing where it matters most (west-facing windows, big sliders)
• Tweaking the plan for orientation (swap living and bedroom zones, shift window sizes)
• Add practical shading (eaves, highlights, adjustable screening)

For a closer look at what’s possible, explore our 8 Star energy-efficient homes to find options that align with your budget, block, and the way you plan to live.

Common Mistakes That Lower Your NatHERS Rating

A quick checklist to avoid:

• Large unshaded west-facing glazing
• Under-specced ceiling or wall insulation
• Lots of “feature windows” without a solar/shading plan
• Layouts that push living areas into the coldest/hottest corners of the home
• Ignoring airtightness details around doors, windows, and penetrations

Improving Your NatHERS Rating with the Right Builder

A strong NatHERS rating is the sum of smart decisions made early and executed properly during the build. For first-home buyers and growing families, the right builder helps guide you toward better design choices from the outset. With JG King Homes, you get just that. We can help you match layout and orientation to your block, while our steel frame construction provides a stable structure that supports quality installation outcomes. 

If you’re aiming for a comfortable home that’s cheaper to run, explore JG King Homes’ energy-efficient home designs.