Confused about NatHERS, BASIX, and BESS? Certified Energy breaks down the key differences between Australia’s leading sustainability assessment systems and when you need each one.
NatHERS, BASIX, and BESS are three of Australia’s most significant sustainability assessment systems, each serving distinct regulatory roles within building design and construction compliance. NatHERS (Nationwide House Energy Rating Scheme) provides a nationally consistent framework for rating the thermal performance of residential buildings, focusing primarily on energy efficiency through detailed simulation modelling. BASIX (Building Sustainability Index) is specific to New South Wales and mandates targets for water use, greenhouse gas emissions and thermal comfort in residential developments, integrating NatHERS ratings with additional environmental benchmarks. BESS (Built Environment Sustainability Scorecard) is used in Victoria for assessing the broader sustainability performance of new buildings, predominantly within the planning permit process, covering energy, water, indoor environment quality and stormwater management.
While all three contribute to Australia’s sustainability objectives, their scopes, regulatory requirements, and compliance pathways differ. NatHERS is nationally recognised and often forms the foundation for state-based schemes like BASIX and BESS, which layer additional local requirements on top of the national minimum standards.
The requirement for each assessment depends on project location, building type, and the stage of design or approval. NatHERS assessments are mandatory for most new residential constructions and major renovations nationwide, ensuring compliance with minimum energy efficiency standards set out in the National Construction Code (NCC).
BASIX certification is compulsory for all residential development applications in New South Wales, including new homes, alterations and additions. BASIX integrates NatHERS star ratings but also demands water and energy reduction targets specific to NSW’s environmental context. In Victoria, BESS is typically required by local councils for planning permits on residential and mixed-use developments, operating alongside or in addition to NatHERS assessments to ensure a comprehensive sustainability outcome.
NatHERS forms the backbone of residential energy assessment in Australia, providing a standardised methodology for evaluating thermal performance. State-based schemes such as BASIX in NSW and BESS in Victoria build on the NatHERS framework, leveraging its modelling outcomes while introducing additional criteria tailored to local environmental priorities and legislative goals.
By integrating NatHERS with state-based programs, building practitioners ensure compliance with both national and state-specific regulations. This layered approach enables more rigorous environmental performance outcomes, supporting Australia’s broader climate and sustainability objectives and addressing the unique challenges posed by different climatic zones and urban settings.
Certified Energy recognises the complexities of navigating multiple compliance frameworks across different jurisdictions. Our integrated sustainability consultancy streamlines the assessment process, ensuring projects meet or exceed the requirements of NatHERS, BASIX and BESS within the context of current legislative and safety standards.
By leveraging multidisciplinary technical expertise, Certified Energy delivers tailored advice and reporting for residential and commercial developments, supporting project owners, architects, and engineers through every stage of compliance. Our commitment to quality assurance, risk management and ongoing regulatory updates positions us as a trusted partner in achieving robust, future-ready sustainability outcomes.