BASIX (Building Sustainability Index) assesses the energy and water efficiency of your development. It is one of the most important planning tools currently operating in NSW to ensure buildings are being developed to operate in a sustainable manner. In NSW the State Government requires that a BASIX Certificate is attached to all development plans when submitted for DA approval.

It has 3 sections – water, thermal comfort and energy. A BASIX certificate is generated once your development successfully meets all of the criteria in each of these sections.   


Here are some tips to help you meet your BASIX requirements if your project is not passing:


1. Water:    

  • Showerhead rating:  Increase rating
  • Toilet, kitchen taps, bathroom taps ratings: Increase rating
  • Rainwater tank volume:       
    - Increase from 2000L (standard) to higher capacity 
    - Increase Roof area connected to the tank (60%-70% to 80%-90% of total roof area)


2. Energy:

  • Hot water system (default selection gas instantaneous)
            - Increase rating
            - Change selection to electric heat pump (air sourced) or a solar option 
  •     - Cooling systems (default selection 1-phase air-conditioning)
            - Reduce rating
            - Day-light zoned between bedroom and living areas
            - Change to ceiling fans 
  •     - Heating system (default selection 1-phase air-conditioning)
            - Reduce rating
            - Remove system 
  •     - Other
            - Select well ventilated refrigeration space
            - Select outdoor clothes drying line
            - Select indoor clothes drying line 


3. Thermal:

  • - Heating and cooling loads both too high 

            - Change the insulation of external walls
            - Increase R-values of celling insulation
            - Change the insulation of Internal wall share with garage
            - Use double glazed windows (start with windows facing north)
  •     - Heating loads too high
            - Use high solar e gain windows
            - Change roof and external wall colour to dark
            - Reduce overshadowing
  •     - Cooling loads too high
            - Adjust window opening percentages
            - Use low solar gain windows (in kitchen/living area)
            - Change roof and external wall colour to light
            - Examine plans to locate whether can increase overshadowing


NSW Government, 2018. BASIX assessment – BASIX (Building Sustainability Index). [ONLINE] Available at: [Accessed 09 April 2018].

For more information on BASIX click here.




Deniro Stocks

Written by Deniro Stocks

Deniro Stocks is the Digital Marketing Manager of Certified Energy