Using the rating tool as a design instrument rather than a certificate.
While the NatHERS pathway can provide significant detail around the thermal performance of the building fabric, we can use this information to optimise the design of the building to minimise the energy required to heat and cool the home. Combined with a comprehensive whole of home assessment, we can help you refine the design of a dwelling to reach a net zero energy usage, while still finding a realistic, cost effective pathway.
Studio Bun can offer a service of tailored assessments and iterations centred around the refined modelling of the building fabric and services specifications to get the optimal energy efficiency for your project.
This process will still ensure that all compliance requirements and certifications are met, but additional time will be spent to ensure the optimal outcome for your design.
Iterative thermal performance modelling in FirstRate5, used to improve a dwelling's rating, comfort and running costs beyond the NCC 2025 minimum, with a written report on each option tested and its effect.
This is an advisory service alongside certification.
Suited to owners and designers who want to maximise the thermal performance of a home, projects targeting well above 7 stars, and clients weighing the capital cost of a specification against its running cost over time.
Stage 1 — Project Initiation. Studio Bun reviews your drawings, specifications and brief, identifies the NCC 2025 requirements that apply to the project, and issues a proposed compliance pathway together with a fixed fee covering the full process.
Stage 2 — Baseline Assessment & Design Advice. We model the design as currently drawn to establish a baseline, then issue a Preliminary Assessment Report identifying the variables with the greatest influence on this particular design and the improvements available at each.
Stage 3 — Design Iteration & Optimisation. Between the preliminary and final reports we allow two rounds of minor changes to the design, and a meeting to review the recommendations. From here we can focus on cost efficiency or on performance, as the project requires.
Stage 4 — Final Reporting. We issue an optimisation report recording each option tested, its effect on the star rating, Whole of Home score and estimated heating and cooling load, and a recommended specification. Certification, where required, is issued under the relevant compliance service.
A baseline assessment of the first design iteration
Iterative modelling of nominated design variables, including orientation, glazing area and specification, shading and eave depth, insulation levels, thermal mass and air tightness
A sensitivity study showing which variables move the result most on this particular design
Options presented with their effect on star rating, Whole of Home score and estimated heating and cooling load
Product guidance for glazing and insulation available on the Australian market
A design review meeting to work through the options
A written optimisation report
Relevant NatHERS and Whole of Home certificates as required
A few items sit outside this scope and can be quoted separately:
Cost estimating and quantity surveying
Passivhaus certification or PHPP modelling
Mechanical ventilation or heat recovery design
Condensation risk analysis
Construction detailing
This service assumes a Class 1 dwelling with drawings sufficiently developed to model. Best value is obtained when engaged at concept or early design stage.
Studio Bun offers fixed sum packages for design optimisation, priced on the number of variables tested and the number of iterations required.
Contact us for a quote.
Why go beyond 7 stars if 7 is all I need to comply?
Because the star rating is a proxy for how the home actually performs — comfort, energy bills and resilience to heat. Going from 7 to 8 stars typically means noticeably lower heating and cooling costs and a more comfortable home in Melbourne's swings between hot summers and cold winters. For many owners the extra performance pays back over time; for others it's about doing the project properly. Optimisation tells you exactly what each step is worth so you can decide.
What's the difference between optimisation and a standard NatHERS assessment?
A standard assessment models your design and certifies that it meets the minimum. Optimisation actively explores how much better it can be — running multiple design variations and costing each performance gain — before you commit. One answers “does it pass?”; the other answers “how good can it be, and what does that cost?”
How much does an extra star cost?
It depends entirely on the design — sometimes a free win from reorienting a window or adjusting shading, sometimes a real cost in higher-spec glazing or insulation. The point of this service is to find out for your specific project, rather than guessing, so you're never paying for performance that isn't worth it.
Will optimisation lower my energy bills?
A higher performing home needs less energy to stay comfortable, so generally yes, and the Whole of Home side of the modelling looks directly at the fixed appliances that drive running costs. We can model the expected energy outcome as part of the strategy.
Can you optimise an existing design, or does it need to be early?
Both work, but earlier is better and cheaper. The biggest, lowest cost gains come from orientation and glazing decisions made in concept and schematic design. We can still optimise a developed design, there is just less room to move.
Tell me your project and your ambition, and I'll scope an optimisation package.
enquire now