What is a Home Energy Rating?

The Basics

A home energy rating is an assessment of your home's potential energy efficiency on a scale of 0 to 10 stars. In Australia, this is formally known as a NatHERS (Nationwide House Energy Rating Scheme) rating.

What Does It Measure?

A NatHERS rating measures how much energy your home needs for heating and cooling to maintain comfort. The rating considers:

• Building design and orientation
• Insulation levels
• Window types and placement
• Climate zone
• Air infiltration and ventilation
• Building materials and thermal mass

The Star Rating System

The NatHERS scale ranges from 0 to 10 stars:

• 0-3 stars: Poor energy efficiency, high running costs
• 4-5 stars: Basic efficiency (minimum requirement for new homes in most states)
• 6-7 stars: Good energy efficiency, standard for new builds
• 8-9 stars: Excellent efficiency, significantly lower energy costs
• 10 stars: Outstanding efficiency, minimal heating and cooling required

Each additional star can reduce heating and cooling energy use by approximately 10-15%.

Why It Matters

A home energy rating is crucial because it:

• Saves money: Higher rated homes have lower energy bills
• Increases comfort: Better thermal performance means more consistent indoor temperatures
• Adds value: Energy-efficient homes are more attractive to buyers
• Reduces emissions: Less energy use means lower carbon footprint
• Meets regulations: Required for new builds, major renovations, and property sales