NatHERS for Knockdown Rebuilds: What Is Different

Knockdown rebuilds are booming across NSW, especially on established blocks in good suburbs. For energy compliance, the demolition resets the clock: your new home is assessed as a brand-new dwelling and must meet the full 7-star and Whole-of-Home standards. The upside is a clean slate to design it right.

A new home, new rules

Because nothing of the old house remains, there is no partial-compliance shortcut. The replacement home is a new build in the eyes of the assessment, so it needs a full NatHERS rating and BASIX Certificate like any new dwelling.

The advantage of a blank slate

Unlike a renovation constrained by existing walls, a knockdown rebuild lets you optimise from scratch. That means you can place living areas to the north, size windows to their orientation and design eaves correctly, the very levers that deliver an efficient 7 stars cheaply.

• Orientation. Set the floor plan to the sun, not the old footprint.
• Glazing. Right-size and place windows from first principles.
• Shading. Design eaves and shading into the elevations.
• Services. Choose efficient hot water and consider solar from day one.

Watch the established-block traps

Older blocks often have fixed constraints: neighbouring buildings that overshadow, heritage controls or tight setbacks. These can limit orientation and solar access, so it pays to test the energy result early rather than assuming a new build will pass automatically.

Frequently asked questions

Can I keep one wall to avoid new-build rules? Retaining token structure to dodge compliance is risky and rarely worthwhile. A clean new build is simpler and usually better.

Does the old slab help? Only if reused structurally and assessed accordingly. The new design still has to meet current standards.

Planning a knockdown rebuild? Send us the new plans and we will lock in an efficient 7 stars.