Articles - Certified Energy

7 Star Homes in Australia — What Actually Defines a High Performance Home

Written by Team CE | Oct 23, 2024 4:34:43 AM

A 7 star NatHERS rating is now the minimum standard for most new homes in Australia.

But while the requirement is clear, what actually defines a well-performing home is often misunderstood.

Achieving 7 stars is not about adding more upgrades.
It is about how the home is designed from the beginning.

This article explains what makes a 7 star home, how the rating works, and what to focus on when designing or building.

What is a 7 star home

A 7 star home is designed to maintain comfortable indoor temperatures with minimal reliance on heating and cooling.

This is measured using the Nationwide House Energy Rating Scheme (NatHERS), which rates homes from 0 to 10 based on thermal performance.

A higher rating means:

  • Less energy is required to maintain comfort
  • The home performs better passively
  • Indoor temperatures remain more stable

Importantly, the rating focuses on the building design — not appliances or occupant behaviour.

What actually drives a 7 star rating

A common misconception is that higher ratings come from adding features.

In reality, performance is driven by a small number of key design decisions.

1. Orientation

The position of the home relative to the sun has the biggest impact.

  • North-facing living areas capture winter sun
  • Shading controls summer heat
  • Poor orientation increases energy demand

2. Layout and zoning

How spaces are arranged affects how heat moves through the home.

  • Living areas benefit from sunlight
  • Bedrooms can be positioned for stability
  • Zoning reduces unnecessary heating and cooling

3. Windows and glazing

Windows are one of the most influential elements in a NatHERS model.

Performance depends on:

  • Size and placement
  • Type of glazing
  • Exposure to sun and wind

Double glazing can help — but only when used in the right context.

4. Shading

Shading is often underestimated.

It controls:

  • Summer heat gain
  • Glare and comfort
  • Overall energy demand

Well-designed shading can reduce the need for high-spec glazing.

5. Building materials and insulation

The building envelope determines how heat is stored and transferred.

  • Insulation reduces heat loss and gain
  • Thermal mass helps regulate temperature
  • Construction type affects overall performance

How NatHERS assessments work

A NatHERS assessment uses thermal modelling software to simulate how a home performs across a full year.

The process includes:

  1. Building a digital model of the home
  2. Simulating internal temperatures
  3. Calculating heating and cooling demand
  4. Assigning a star rating from 0 to 10

The result reflects how efficiently the home maintains comfort.

Benefits of a 7 star home

Lower energy costs

Higher performing homes require less heating and cooling.

Improved comfort

Temperatures remain more stable throughout the year.

Better long-term value

Energy-efficient homes are increasingly valued in the market.

Resilience to climate conditions

Well-designed homes perform better in extreme temperatures.

Common mistakes when aiming for 7 stars

❌ Relying on upgrades instead of design

❌ Oversizing windows without considering orientation

❌ Adding double glazing without addressing layout

❌ Ignoring shading

❌ Treating compliance as a checklist

Can you upgrade an existing home to 7 stars

Yes — but it is often more complex than designing for it from the start.

Typical upgrades include:

  • Improving insulation
  • Upgrading windows
  • Sealing air gaps
  • Adjusting shading

The effectiveness depends on the existing design.

Is 7 stars enough

7 stars is a compliance benchmark — not necessarily optimal performance.

Some homes can achieve higher ratings with minimal additional cost when designed well.

The goal should not be to “hit 7” — but to create a well-performing home.

Final thoughts

A 7 star home is not defined by features — but by design.

When orientation, layout, glazing, and materials are considered together, strong performance can be achieved efficiently.

The earlier these decisions are made, the easier and more cost-effective the outcome.