As discussed in a previous blog article, the changes to the Energy Efficiency Provisions that were introduced with the NCC 2019 on the 1st of May 2019 have a mandatory adoption date of the 1st of May 2020.
What are the main changes for residential dwellings?
The 6 Star* minimum rating remains in place for NatHERS (software-rated) assessments, however a new requirement for minimum heating and cooling loads has been added.
The 6 Star rating is based on the number of MJ/m2 that the area adjusted building is expected to use in artificial heating and cooling across a 12-month period. It takes many different factors into account, and aims to closely estimate the energy use of the building over a year. See a previous blog article here for more information.
Under NCC 2016, the MJ/m2 could be mainly in heating, mainly in cooling, or evenly weighted amongst heating or cooling. The CSIRO determined from analysis of ratings performed that there were 5% of 6 Star buildings that were designed and built in such a way as to require almost all of their artificial temperature regulating in either heating or cooling. While these dwellings met the 6 Star requirement, they were either extremely cold in winter or extremely hot in summer and required almost all of their artificial temperature moderating in one season or the other. The aim of the introduction of the heating and cooling load caps is to ensure that a dwelling is not using too much energy in either heating or cooling, but is more thermally comfortable and Energy Efficient all year round.
NCC 2019 introduces heating and cooling load limits (in addition to the existing 6-star requirements) for all Class 1, 2 and 4 buildings assessed under the NatHERS software. For those familiar with BASIX, this is similar to the heating and cooling loads that have existed with the BASIX legislation for a number of years.
What are the other minor changes?
There are tighter details for the Reference Building Requirements when using “Verification Using a Reference Building” Method of Assessment, as well as the introduction of Verification of Building Envelope Sealing as an available method for demonstrating compliance with P2.6.1 (f) which relates to the sealing of the building envelope against air leakage.
Is everything else staying the same?
The Objective (to reduce greenhouse gas emissions), Functional Statements, Performance Requirements and State exemptions are all unchanged from NCC 2016 Volume Two to NCC 2019 Volume Two. Dwellings can still demonstrate compliance with the Performance Requirements in one of four ways (NatHERS Energy Rating, Deemed to Satisfy Elemental Provisions, Verification Using a Reference Building, or demonstration of a Performance Solution).
All of the Deemed to Satisfy (DTS) requirements remain unchanged.
How will the changes affect my project?
If the project is in the Northern Territory, Tasmania or NSW, there will be no change. The NT is still assessed under BCA 2009, NSW is covered by BASIX, and Tasmania’s climate zone exempts it from the new heating load requirements, as all of the energy is expected to be used to heat the dwelling.
For a designer, builder, or homeowner submitting plans for assessment in other States or Territories, there will not be a significant change in the process. Most dwellings achieving 6 stars will meet the new heating and cooling load caps. The assessor will need to ensure that the heating and cooling load caps are met, and based upon our experience, this will ensure some additional tweaking of colours, insulation levels and glazing selection for about 10% of dwellings we assess, in order to achieve compliance.
You should see these new heating and cooling load requirements being referenced in the Energy Assessment report that you receive for your projects from 1st May, 2020.
BERA is ready to assess homes under the new legislation.
Contact us today for a quote on your upcoming project.
* Note that there are some State based and Climate Zone based exceptions allowing for 5.0 or 5.5 Stars to achieve compliance, but for the purposes of this article, we will discuss the 6 Stars.)