Understanding BASIX Requirements in NSW

If you are planning any residential construction or major renovation in NSW, you will need to understand BASIX requirements. The Building Sustainability Index (BASIX) is a mandatory environmental assessment tool that applies to most residential development in New South Wales, designed to deliver water and energy savings while improving thermal comfort.

What is BASIX?

BASIX stands for Building Sustainability Index. It was introduced by the NSW Government in 2004 to ensure new homes and renovations meet minimum sustainability standards. BASIX assesses three key areas:

• Water consumption: Targeting a 40% reduction compared to typical homes
• Energy consumption: Targeting reductions in heating and cooling loads
• Thermal comfort: Ensuring homes maintain comfortable temperatures with minimal energy use

When is BASIX Required?

A BASIX Certificate is required for most residential developments in NSW, including:

• All new homes and dwelling houses
• Granny flats (secondary dwellings)
• Dual occupancies and duplexes
• Multi-unit residential developments
• Alterations and additions over $50,000 in value
• Swimming pools and spa pools (separate certificate)

There are some exemptions, including heritage buildings and certain types of alterations, but these are limited. Most residential projects on Sydney's Lower North Shore will require BASIX compliance.

BASIX Target Scores

To obtain a BASIX Certificate, your project must achieve minimum target scores in water and energy/thermal comfort. The specific targets vary depending on:

• Type of development (house, unit, alteration)
• Climate zone (Sydney is in Climate Zone 5 - Warm Temperate)
• Whether it is a new building or alteration

For new houses in Sydney, typical targets are:

• Water: 40 points (40% reduction)
• Thermal Comfort: Pass requirements for heating and cooling loads
• Energy: Varies but typically requires significant reduction in energy consumption

Common BASIX Commitments

To achieve required BASIX scores, projects typically incorporate various sustainability features. Common commitments include:

Water Efficiency

• 3-star WELS rated taps and showerheads
• Dual flush toilets (4/3 star WELS rating)
• Rainwater tanks connected to toilets, laundry, or external taps
• Water-efficient dishwashers and washing machines
• Flow restrictors on fixtures

Energy and Thermal Comfort

• Insulation in walls, ceilings, and floors (specific R-values)
• Energy-efficient glazing (appropriate glass selection)
• External shading devices on windows
• Light-colored roofing materials
• Sealing gaps and draft-proofing
• Energy-efficient hot water systems (heat pump or solar)
• LED lighting throughout

How We Help with BASIX

As experienced building designers, BASIX is integrated into our design process from day one:

• We design with BASIX requirements in mind, not as an afterthought
• We prepare and lodge BASIX Certificates as part of our standard service
• We recommend practical, cost-effective measures that suit your project
• We ensure commitments are realistic and achievable during construction
• We coordinate with builders to ensure BASIX compliance during construction