Caution advised: NatHERS tools unsuitable for the NCC reference building Verification Method V18.104.22.168
The National Construction Code includes an option (V22.214.171.124 Verification Using a Reference Building) to calculate the energy consumed by a reference building that includes all the deemed to satisfy requirements in the NCC and compare that to the calculation of the energy consumed by the proposed building. Both calculations are done under conditions set out in the NCC.
It has come to CSIRO’s attention that some reference building assessments are being undertaken using NatHERS accredited tools for the calculation of the energy consumed by the reference and planned buildings. Users of NatHERS accredited tools need to be aware that these tools use a different set of conditions to those set out in the NCC, so that NatHERS tools may not be suitable to provide a Reference Building Verification to show compliance with the NCC.
V126.96.36.199 states that:
“c) The calculation method used must be capable of assessing the heating load and cooling load by modelling—
(v) space temperature settings in the range 20ºC to 21ºC for heating and 25ºC to 28ºC for cooling;”
All NatHERS tools use set thermostat settings of between 22.5 º Celsius and 27.0 º C for cooling (depending on Climate Zone). For heating living spaces (including kitchens and other spaces typically used during the waking hours) a heating thermostat setting of 20° C is used and bedroom spaces (including bathrooms and dressing rooms, or other spaces closely associated with bedrooms) a heating thermostat setting of 18°C from 7-9 am and from 4 pm to midnight and a heating thermostat setting of 15°C from midnight to 7 am is used.
Users are unable to change the relevant conditions in the NatHERS accredited tools.
Therefore in most instances NatHERS tools are not appropriate for use in demonstrating compliance National Construction Code under V188.8.131.52. These tools are only designed and maintained to be used under the NatHERS pathway in the NCC and CSIRO is not responsible for any consequence due to such misuse of NatHERS accredited tools. Construction of buildings rated less than 6 stars using NatHERS tools may lead to poor comfort and energy performance in the finished dwelling.
Governance review of NatHERS
The NatHERS Administrator recently engaged ACIL Allen Consulting to undertake an independent governance and operational review of NatHERS. This Review assessed the effectiveness of the current NatHERS governance framework and operating model in delivering the Scheme’s objectives.
The Review has been completed and the COAG Energy Council’s Energy Efficiency Advisory Team (representing the Commonwealth, states and territories) has developed a draft response to the recommendations from the Review.
The final report and draft response can be found on the NatHERS website under ‘NatHERS Governance and Operational Review’: http://www.nathers.gov.au/governance. Some of the observations made are already being addressed.
New disclosure rating tool being developed
By now many of you will have heard some of the buzz around a new tool being developed by Energy Inspection based on CSIRO technology, currently referred to as the Carbon Emissions Management Platform (CEMP). In addition to thermal ratings, the new tool will include energy assessment of house appliances, solar PV, battery storage and has adjustable occupancy settings to reflect individual lifestyles.
The CEMP is best thought of as an online platform bringing together the best data entry and user interface options, the open studio building model developed by the US National Renewable Energy Laboratory, the Chenath engine and the CSIRO AUSZEH Design algorithms in a modern, cloud-hosted environment. The finished platform intellectual property will be owned by CSIRO and licenced to Energy Inspection to distribute. The total investment will be over $3 million. (Note: this development does not change licensing arrangements for existing NatHERS tools, or prevent others from developing new NatHERS based tools)
A dedicated team of developers commenced work on the CEMP in September. The first release of the program to beta-testers is expected in early 2017 and will likely include mainly the thermal performance core of the software. Further releases will add features until the complete tool is released sometime close to the end of 2017.
New Low Carbon Living CRC Project launched
The Co-operative Research Centre for Low Carbon Living (CRC LCL) recently launched its project RP1024 which will inform the development and validation of this and other tools. The CRC media release is here http://www.lowcarbonlivingcrc.com.au/news/news-archive/2016/09/unisa-media-release-launch-rp1024-nextgen-ratings-tool-project
The RP1024 project will harness CRC participant resources to provide significant research into several issues of concern to users of Chenath-based software. These include;
- A review of the NatHERS assumptions and settings
- Cooling model investigations
- Improved outputs focussed on increasing compliance
- Supporting materials including information and training
NatHERS software in the National Construction Code
Recently, a proposal was included in the draft National Construction Code to allow a wider range of modelling software to be used to evaluate the compliance of planned class one and class two buildings with the energy efficiency requirements of the Building Code of Australia.
The proposal was included in a draft for discussion in late 2015. CSIRO and many others submitted comments on the proposal. Among other consistency and quality assurance concerns, there was considerable concern that the proposed process to be used for non-NatHERS compliant software would have significantly reduced the stringency of the requirements and potentially left new home occupiers with housing that required significantly larger amounts of energy to maintain comfort than current construction practice. The ABCB decided not to include this change in the 2016 version that is now available from the ABCB website.
For more details see article on Energy efficiency and the increased use of performance in the ABCB newsletter.
ASBEC releases a National Framework for Residential Ratings
In January 2016, the Australian Sustainable Built Environment Council (ASBEC) released a paper calling for a nationally consistent approach to residential ratings to assess the sustainability of residential buildings, set minimum standards, benchmark building performance, and communicate value.
This is intended to help homeowners to understand and value sustainability elements, and enable industry to deliver better quality, more sustainable products and services to renovators and homebuyers.
ASBEC has identified three key elements of an effective framework:
- Set minimum regulatory performance standards in new buildings for each of building energy, thermal comfort, water and other sustainability issues
- Provide benchmarks for market comparison of best practice sustainability performance; and
- Deliver communication messages explaining the value of sustainability features to renovators and homebuyers, including at point of sale and lease.
Read more at http://www.asbec.asn.au/research/
NatHERS accreditation of BERS Pro v184.108.40.206 (3.13)
Energy Inspection have advised that the NatHERS Administrator has granted accreditation of BERS Pro v220.127.116.11 (3.13) from 1 May 2016.
Please refer to the NatHERS website for details.
FINE 4Rate: A BIM Solution for transferring data into AccuRate Sustainability
4M Australia has developed and is launching FINE 4Rate, a customised Building Information Modelling (BIM) application. The software allows Energy Assessors to utilise the benefits of BIM in conjunction with the AccuRate Sustainability software.
FINE 4Rate’s power features are:
• 3D BIM interface that populates the AccuRate Sustainability software with all building, zone and shading scheme data
• Easy to learn and use 2D 3D design AutoCAD(R) like interface
• Graphic interface allowing for easy editing and visual understanding of the building
• The familiar AccuRate Sustainability materials and element libraries are used
• For multi-dwelling projects, each individual dwelling file is automatically produced via an xml export-import function directly from the single 3D BIM model of the building
• All necessary building elements are defined in the 3D model including additional information such as zones, vertical shades, horizontal shades, wing walls, ceiling penetrations, and then exported to the AccuRate Sustainability project file.
4M Australia Pty Ltd is the Australia and New Zealand representative of 4M, a global software company which provides the Engineering community with advanced CAD software
Contact details: +61 2 8006 5070, firstname.lastname@example.org, www.au.4mbim.com.
Note: This content has been submitted by 4M Australia Pty Ltd. FINE 4Rate was not developed by CSIRO and is not a CSIRO product. CSIRO has not tested and does not endorse FINE 4Rate. If you use FINE 4Rate you must ensure the data entered into AccuRate Sustainability using FINE 4Rate is correct and appropriate before finalising a rating.