How a NatHERS Consultant Saves Your Build
8 June 2026
If you are planning a residential development, a major renovation, or a new home build in Australia, hitting compliance targets is no longer just a checkbox exercise. With the National Construction Code (NCC) mandating a strict minimum 7-star thermal rating alongside the complex Whole of Home energy budget, the structural and financial stakes of your design are incredibly high.
Working with an accredited NatHERS consultant early in the design phase is the difference between a smooth, cost-effective approval and a devastatingly expensive mid-build redesign.
Here is exactly how a NatHERS energy assessment protects your project, your budget, and your timeline.
What Does a NatHERS Consultant Actually Do?
A Nationwide House Energy Rating Scheme (NatHERS) consultant uses advanced, government-accredited simulation software (such as BERS Pro, Hero, or FirstRate5) to model your architectural plans.
By analyzing the building's orientation, materials, insulation, glazing, and local climate zone, the consultant estimates the annual thermal energy required to keep the home comfortable.
An expert consultant doesn’t just issue a pass/fail certificate. They look at your project holistically across two distinct regulatory baselines:
- The Thermal Star Rating (Out of 10): Measuring how well the home’s fabric retains or rejects heat.
- The Whole of Home Assessment (Out of 100): Factoring in the energy consumption of major fixed appliances (heating/cooling, hot water, lighting) offset by on-site solar PV generation.
Why You Need to Engage a NatHERS Consultant Before Council Submission
Many builders and owner-builders make the mistake of leaving their energy rating until the final structural plans are drawn up. If those plans fail to meet the 7-star threshold, fixing the problem retroactively is incredibly costly.
An experienced energy assessor steps in during the preliminary concept stage to optimize three critical areas:
1. Orientation and Layout Optimization
A slight shift in a building's footprint or shifting the living areas to face true North can dramatically lift a thermal rating. Your consultant can show you how to leverage passive solar design before a single brick is laid, reducing your reliance on expensive mechanical heating and cooling.
2. Glazing Specifications Without Over-Specifying
Glass is usually the weakest link in a building envelope. If your design falls short, blindly upgrading every window to high-end, thermally broken double-glazing can blow out a budget by tens of thousands of dollars. A specialized consultant runs iterative software simulations to find the exact combination of window sizes, tints, and frame types required to hit compliance—saving you from over-specifying.
3. Smart Material Selection
From choosing between a lightweight clad wall and high-thermal-mass brickwork, to calculating the exact R-value insulation needed in double-storey voids or concrete slabs, a consultant models different construction assemblies to find the most cost-effective path to compliance.
The True Cost of Delaying Your Energy Assessment
When an energy rating is treated as an afterthought, compliance failures result in forced, reactive design changes.
1. Phase Engaged
Concept Phase (Recommended)
Typical Outcome
Passive design adjustments, optimized orientation, targeted glazing selections
Cost Impact
Lowest Cost (Saves money on materials)
2. Phase Engaged
Final Working Drawings
Typical Outcome
Forced upgrades to expensive performance glass, upgraded insulation, or modified wall thicknesses.
Cost Impact
Moderate to High Cost
3. Phase Engaged
Mid-Construction / Post-DA
Typical Outcome
Delays in construction certificates, structural variations, council re-submissions.
Cost Impact
Extremely High Cost + project delays
A Note for NSW Builders: In New South Wales, your NatHERS thermal performance data directly feeds into your BASIX (Building Sustainability Index) certificate. Ensuring your NatHERS data is perfectly optimized is the critical first step to unlocking your overall BASIX compliance.
Choosing the Right NatHERS Consultant
When hiring a professional to handle your project's compliance, ensure they check the following boxes:
- Accredited & Insured: They should be fully accredited with an Assessor Accrediting Organisation (AAO) like Design Matters National (DMN) or the Australian Building Sustainability Association (ABSA), carrying a minimum of $2M Professional Indemnity insurance.
- Software Proficiency: They should be experts in current-generation, Whole-of-Home capable software platforms.
- Consultative Approach: Look for a partner who offers actionable redesign suggestions, not just a black-and-white certificate delivery.
By integrating a sustainability expert into your design team early, you eliminate regulatory guesswork, slash your future energy bills, and build a structure that remains comfortable through every Australian season.
Ready to Secure Your 7-Star Compliance Without Blowing Your Budget?
Don't let compliance failures force expensive, mid-build design changes. Involve an accredited NatHERS consultant during your concept stage to lock in cost-effective material selections and optimized glazing plans before you submit to council.
Get a Fast, Professional Compliance Quote
Upload your preliminary drawings or concept plans today, and our team will map out the most efficient path to compliance.
Written by Mark Zangari, NatHERS Consultant @ Assessify
Mark Zangari is a building compliance and sustainability specialist at Assessify, with experience supporting residential development approvals across Australia.
They work closely with builders, designers, developers & home owners to navigate NatHERS requirements, development applications and construction compliance.
With a focus on practical, regulation‑aligned guidance, Mark helps clients identify compliance risks early, avoid approval delays, and ensure sustainability commitments are met throughout the design and build process.