Short answer
VURB assessments evaluate all major energy influencing components: building envelope (walls, roofs, floors), glazing (windows, doors, shading), insulation, air movement, building sealing, lighting, HVAC (heating, ventilation, air conditioning) and internal services. Performance across all these must be equal to or better than the reference building to comply.
Full answer
VURB assessments evaluate a wide range of design elements that impact a building’s energy performance. These include the building fabric—such as the roof, ceiling, walls and floors—focusing on thermal resistance, materials, R-values and thermal mass. Glazing and shading are assessed based on glass type, frame, orientation, glazing-to-floor ratio and any shading devices. Insulation in the roof, walls, floors and ceiling is reviewed for quality, installation and continuity. Sealing and airtightness are examined to identify potential leakages around windows, doors, external walls, roof lights and ductwork. Lighting and artificial power are considered, including the efficiency of interior and external lighting, power loads and lighting controls. HVAC and mechanical services are assessed for the efficiency of heating and cooling systems, ductwork, pumps, ventilation and controls. Other services, such as water heating, pool or spa equipment and system monitoring, are also reviewed where relevant. These elements are not evaluated in isolation; they interact within the simulation model. For instance, increased glazing can lead to higher solar gain, raising cooling demand and putting additional load on HVAC systems—unless mitigated through shading or improved glazing specifications. Overall compliance is based on whether the proposed building meets or outperforms the reference building in terms of predicted energy use or emissions.
Why this matters
Understanding which design elements affect energy performance allows you to make smarter trade-offs during the design process—for example, deciding whether to invest in higher performance glazing or incorporate effective shading. It also supports better decision-making early in the project, as certain choices like large glazed areas may increase compliance complexity or cost, requiring offsets elsewhere in the design. Being informed helps you avoid unexpected expenses or last-minute redesigns if a certifier identifies non-compliant features. Importantly, these choices also have long-term implications for energy bills, indoor comfort and the building’s overall sustainability and emissions impact.
How Certified Energy can help
We review your design elements early to identify any areas that may underperform before proceeding with detailed modelling. Our team suggests cost-effective strategies to enhance performance, such as adjusting building orientation, adding shading or improving airtightness. We also conduct sensitivity studies to highlight which changes will provide the greatest energy efficiency benefits relative to their cost. Finally, we deliver a comprehensive report with detailed breakdowns, helping you understand exactly where performance improvements or shortfalls have occurred.
Related regulations
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NCC Section J Parts covering Building Fabric (J1), Glazing (J2), Sealing (J3), Lighting (J6), HVAC / Ventilation (J5) etc.
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Reference Building Verification method (JV3) in NCC ‒ rules for how comparison must be done.
Helpful resources
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