Sustainability FAQ

WHAT IS A BASIX CERTIFICATE?

Introduced in 2004, BASIX (Building Sustainability Index) is a regulatory New South Wales specific scheme designed to make all subsequent future developments under the regulation 40% more greenhouse gas efficient than those that were built before the scheme.

In short, it’s an assessment most residential buildings need to have completed during the development application stage when applying for a council permit to build. It consists of a thermal component (NatHERS or DIY assessment) an energy efficiency component and a water usage component, all three of which must be satisfactorily passed by truthfully entering data into the online tool.

WHEN DO I NEED A BASIX CERTIFICATE?

If your project is governed by New South Wales legislation (being built in NSW) and is a new development then yes. Furthermore any alteration or addition greater than the sum of $50,000 to an existing home will also need one. Note that the BASIX  applies to class 1 and 2 and some class 4 buildings under the BCA Section J. These are residential buildings that we may consider regular houses and do not apply to commercial developments.

WHAT IS A NATHERS ASSESSMENT?

NatHERS (Nationwide house energy rating scheme) is a mandatory Australia wide star rating that must be calculated for all new developments or large alterations and additions. Unlike the BASIX, NatHERS applies to every state and territory and a minium of 6 stars must be acheived with some concessions and exemptions being given uniquely by each state.

Essentially, NatHERS is a thermal simulation protocol that tries to forecast the heating and cooling loads of a building per square meter which forces designers to build more energy efficient buildings in the long run. Our Assessors use one of the three approved softwares codeveloped by the CSRIO (BERSpro) to turn proposed designs into an accurate star rating.

In NSW only, a NatHERS assessment is one of the 3 components of the BASIX. The New South Wales government also provides a DIY method in completing the thermal part of the BASIX which is a simple online calculator that gives a rough calculation. At times this may be preferable to save on costs as no assessor or simulation is needed, however the input options it provides are very limited and often cost the end user more in the long run. Only trained assessors can perform the software simulation component as there are many quality control regulations to follow.

WHEN DO I NEED A NATHERS ASSESSMENT?

If your project is a residential (class 1, 2 and some class 4) building then you will likely require a NatHERS rating that passes the national 6 star requirement. New South Wales users may opt for the DIY method, however it is generally not recommended as full thermal simulations helps optimise the building in many ways, discovering flaws and design limitations that the DIY method cannot model for. For the end user this can mean spending a few hundred to save on a few thousand in operating costs.

WHAT IS THE SECTION J?

Section J is a part of the National Construction Code that requires all new proposed developments to comply with it’s performance requirements. The section itself is concerned with thermal energy and energy requirements guidelines that all class 2 to 9  buildings (almost everything except small residential homes) must comply with.

Dural Group offers a complete section J report that covers:

  • Part J1 – Building Fabric
  • Part J2 – Glazing
  • Part J3 – Building Sealing
  • Part J4 – Currently does not apply
  • Part J5 – Air-Conditioning and Ventilation Systems
  • Part J6 – Artificial Lighting and Power
  • Part J7 – Hot Water Supply and Swimming Pool and Spa Pool Plant
  • Part J8 – Access for Maintenance and Facilities for Monitoring

There are two methods used to show compliance: ‘deemed to satisfy (DTS)’ and ‘JV3 alternative solution.’ A DTS solution is as the name implies, by showing that the building’s performance measures pass the minimums set out in the NCC guidelines. This is done through calculations, ‘Evidence of Sustainability,’ and expert judgement as outlined in the code itself.

WHEN DO I NEED A SECTION J REPORT?

Nationwide, proposed buildings from class 2 to 9 which comprises of commercial, industrial and large residential projects needs to have a Section J report in the accompanying development application.

WHAT IS A JV3 ALTERNATIVE SOLUTION?

The JV3 alternative solution is an alternative method of showing compliance with Section J of the National Construction Code. Complex buildings that fail to meet the performance requirements of the section can be modelled in 3D and simulated to show that the resulting values already comply or will comply with the code given certain modifications.

The principle behind this type of modelling follows the performance requirements for an existing reference building. In doing so, designers have far more freedom in choosing construction material, orientation, glazing and so forth without falling below the Section J benchmarks. It is similar to the NatHERS method of modelling residential buildings but now for the other classes.

Although the process is costlier and more time consuming, the benefits of a simulation can result in a more efficient building. It is found that building simulated by the JV3 process are more efficient to run in longterm operating costs even if the initial cost is higher.

WHEN DO I NEED A JV3 SOLUTION?

Nationwide, proposed buildings from class 2 to 9 which comprises of commercial, industrial and large residential projects needs to have a Section J report in the accompanying development application. Although this is typically done through the cheaper Deemed To Satisfy method, it is up to the engineer to decide if the project requires a JV3 alternative solution.