PLANNING prone areas (AS 3959). Effectively BASIX DIY METHOD construction requirements for floors, walls, decks, steps, ramps, landings, timber supports, beams and posts for ‘FINE-TUNING’ BAL-12.5 and BAL-19 are lifted to BAL-29 requirements. •It should also be noted that, thanks to HIA lobbying, these construction requirements will be noted directly in After the BASIX targets increased method for light-weight constructions NCC 2019 NSW variations, which will in July 2017, HIA members raised In short, the DIY tool now treats light- help to reduce non-compliances due to concerns about how the DIY method weight cladding in a similar way to the the fact that previous versions of the BCA within the BASIX tool was working. Simulation method using NatHERS- did not reference PBP 06. Particular concern was raised that accredited software. This means that •Another variation to AS 3959 is that granny flats and fairly simple single-storey proposed dwellings with framed walls and/or materials tested to AS 1530.8 parts 1 slab-on-ground house designs were having suspended floors are less reliant and 2 must not ‘flame’. This is not a difficulty achieving a ‘pass’ using the DIY on high-performance glazing and/or change from PBP 06. method. HIA raised these concerns with the dark roofs to satisfy the BASIX thermal •Better Bushfire Outcome – this clause Department of Planning and Environment. comfort requirements. outlines that where development After HIA raised these concerns the This ‘fine-tuning’ has now been involves alterations and additions, strict department commenced a project to implemented, and as a result certain compliance with AS 3959 may not be ‘fine-tune’ the BASIX tool. projects may be able to achieve a ‘pass’ the best outcome for the development. What has been ‘fine-tuned’? for thermal comfort with affordable options For example rather than constructing the using the DIY method, thus saving the addition to BAL-40 it may be a better 1. Options to increase the minimum expense of engaging an accredited assessor outcome to construct the addition to insulation requirements to run a simulation. BAL-29 and provide additional ember Previously the DIY method only had However, it is important to note that due protection to the existing part of the automatic defaults for insulation. Now the to the options available to an assessor when dwelling. Evidence must be provided that user can choose to upgrade the insulation using NatHERS software, certain projects the proposed outcome is better. A bushfire to better reflect insulation commonly used will still achieve a better outcome when design brief (BFDB) can be completed onsite. This will often result in a better ‘simulated’. with all stakeholders including the RFS outcome with less reliance on performance It should be noted that these changes to approve the development under an glazing to achieve a pass. are not ‘BASIX target changes’. Rather alternate solution. Essentially this is the 2. Incorporating floor area correction these changes are ‘tweaks’ to how the NSW RFS process for a performance factors to dwellings with small floor tool works. solution, and further guidance on this can areas (such as granny flats) be found in Appendix 2 of BPB 18. The floor area correction factors applied ...PROPOSED DWELLINGS •When determining the bushfire attack in the CSIRO CheNath engine underlying WITH FLOOR AREAS BELOW level for a site the tables in Appendix 1 software accredited by the Nationwide 190 SQUARE METRES. IN replace those in AS 3959. Energy Rating Scheme (NatHERS) were OTHER WORDS IT WILL 8. Other Development included to correct for the heating and NOW BE EASIER FOR This chapter outlines considerations and cooling loads of proposed dwellings with requirements for construction not covered floor areas below 190 square metres. In GRANNY FLATS TO ‘PASS’ by chapter 7. other words it will now be easier for granny BASIX USING THE DIY Key points: flats to ‘pass’ BASIX using the DIY method METHOD THAN IT WAS •Dual occupancy, multi-dwelling housing, than it was prior to the ‘fine-tuning’. secondary dwellings, rural workers’ 3. Improving the correlation to determine PRIOR TO THE ‘FINE- dwellings and boarding houses must not heating and cooling loads with the DIY TUNING’ exceed BAL-29 on the building envelope, if they do then the provisions of Chapter 5 must be considered even if the land is not to be subdivided. This reflects that complying development can only be carried out on land rated BAL-29 or lower. •‘Technical considerations’ which need to be addressed as part of a development application for multi-storey residential buildings of more than three stories. •Additional considerations for non- residential construction. Planning for Bushfire Protection 2018 can be downloaded for free at www.rfs.nsw.gov.au For more information about the BCA, Australian Standards or any other related matter email nsw_technical@hia.com.au. BUILDING NEWS ISSUE 1/2019P15