The changes that are forecast to be introduced to Section J in 2019 are big. So, grab a coffee and sit back and read on.
The starting point is to forget everything you thought you knew about Section J and start again!
If you are new to this then it is important to know that Section J is part of the Australian building code and relates to ensuring new buildings are energy efficient.
This newsletter has been started and restarted several times. It is easy to get bogged down in the detail of the proposed changes. Let’s try to get an overview first.
The first question might be \”Why change anything?\”
Section J originally came in back in 2006. There have been some small changes in the years that followed but it is essentially the same set of provisions. Reviewing it now is good housekeeping. Has it achieved its objectives? Is there more that can be done and does it take account of changing technology?
The ABCB has put out a lot of material to seek industry feedback and to explain what is potentially coming in 2019. Refer to https://www.abcb.gov.au/Connect/Articles/2017/03/09/Section-J-Overhaul-big-changes-are-coming-your-way to read more.
The goals of the review of Section J are to:
1) increase stringency:
This sounds daunting, but it is not an open-ended opportunity to make things tough for the sake of it. Any proposed change must achieve a cost / benefit ratio of between 1 and 1.5. In other words, any change must make economic sense. The cost associated with meeting the new regulation must be less than the economic benefit of the change.
2) Simplification:
To make the regulation easier to read and understand is a laudable goal. Whether it is achieved we’ll have to wait and see.
3) Increase the emphasis on verification methods:
This is where it can get confusing for the average person wanting to get a construction certificate. The goal of the builder is to get the certificate and build a building. Suddenly, they are told they need a Section J assessment to see if the design complies. Currently the usual way to demonstrate compliance is to go through all the deemed-to-satisfy (DTS) clauses and check if the design complies. However, the DTS clauses are based on a set of averaged out requirements and most buildings are not “average”. There is an alternative route to show compliance and that is to prepare a Performance Solution based on the approved Verification Method, JV3.
Moving to this approach requires a level of sophistication on the part of the applicant. It is no longer a simple regulation to read and comply with. It is now a computer simulation of the behaviour of the building. In our experience the modelling approach always produced a better result because it is tailored to the individual building and it calculates the energy cost of operating the building for every hour of the year for a full year. No averaging out this time.
Modelling does cost more in assessment time, but it usually saves money in other ways during construction.
The analogy is to look at the Basix assessment process. It has a simple process for standard houses but for larger/complex homes and for all multi-unit proposals a simulation method is required.
It looks like Section J is heading that way. More and more projects will be assessed using the simulation method.
To minimise any negative effect of this it will be important allow more time and cost for the assessment, and to ensure there are good quality electronic drawing files available. Preferably in 3D. The electronic drawing files will reduce the time/cost involved in getting the building geometry into the simulation.
What else is new?
Thermal Comfort
For the first time Section J will include thermal comfort. Currently Section J focuses on reducing energy use and thermal comfort is implied. But it is theoretically possible to make a building comply yet not be comfortable. The new regulations will make achieving a minimum comfort level explicit. If you are familiar with Basix you will see the corollary where Basix requires passing thermal comfort standards. Section J is heading that way too.
Currently if you wish to prepare a Performance Solution there is only one Verification Method available; JV3. The new regulations propose to use the simulation component of the Green Star and NABERS rating systems as additional verification methods. Green Star and NABERS have done a lot in recent years to synchronise their simulation protocols. To use their simulation models in Section J is a rational next step.
The level of insulation required in buildings is not changing much. However, the new regulations assume a light-coloured roof is being used. Many of the projects we see are not light coloured in which case a performance solution would be needed if it was important to the designer to use a darker colour.
Thermal breaks are currently required but apparently, they are often over looked. The new regulations will highlight thermal breaks.
Glazing
There are really big changes planned for glazing. Currently we assess the glazing on each floor in any of 8 orientations that might be relevant using a glazing calculator. Before the glazing calculator became available, we did the calculations by hand using 20 pages of look up tables and long strings of additions and multiplications.
The new regulations will treat walls and glazing as one system. This has some benefit in averaging the wall/glazing combination which isn’t available now. But there is still some complexity in it despite the attempt to make it simpler. The proposed regulation is based on a U/SGHC1 ratio of the wall/glazing system which is compared to a bench mark based on a single clear pane window which is 5% of the area of the wall. There has been no mention of a calculator being prepared so it looks like a big spreadsheet is on its way.
In addition to the change in methodology we are told there will be a significant increase in stringency.
Artificial Lighting
When Section J first came in the lighting provisions gave everyone difficulties. Over time, with the introduction of T5 fluoros and LED lights this part has ceased to be a problem.
However, we are now going back to the future with an increase in stringency. The new requirements will be based on LED 2017 technology and effectively halves the lighting power available. There are some other changes relating to the control of lighting, but we don’t think they will give any difficulty.
Lifts
This is a completely new part. There will be requirements fo lifts and they will be based on the international standards; ASHRAE 90.1 and ISO 2574.2(2015)
There are other changes planned for mechanical services, but they are a bit more technical and not included here.
If you are planning on building next year it is important to get on top of the changes beforehand. If you design a building before 1 May 2019 and submit the Construction Certificate application after that date you could have problems if you haven’t anticipated the new regulations in the design.
Please contact us early to discuss the timing of your project to avoid this problem.
1 U is the transmissibility of heat (commonly used in glazing specifications) and is the inverse of the R-value (which is used to rate insulation) and SHGC is the solar heat gain coefficient (also commonly used in glazing specifications)
