If you get a 6 Star Rating on your home, what guarantee do you have that all the Energy Efficiency Measures that were included to achieve that rating are actually put in place in your finished home?
Under current legislation, effectively none.
The National Construction Code requires that your house or unit design achieves a 6 Star Energy Rating, or passes the Deemed to Satisfy Requirements.
However, unless you are an Owner Builder, there is no requirement to actually check that all the elements have been put in place by your builder.
Should you be concerned?
When you sign a contract to have your new home or major renovation completed by a builder or building company, there is a large amount of trust that you place in your builder. Essentially, you are trusting them to build your home so that it is structurally safe, is painted the colours you have chosen, is completed within the time frame that you have agreed upon, and so on.
When mistakes or delays occur, or when corners are cut, it is usually fairly obvious: The tiles do not go to the ceiling in the bathroom as specified, the builders don’t turn up, the window frames are the incorrect colour, and so on. However, many of the Energy Efficiency measures are not as obvious or as well known to many prospective home owners. There could well be inadvertent or deliberate errors that the home-owner does not notice. These involve elements such as:
- The level of insulation in your ceiling – do you know the difference between R1.5 and R3.0 once it has been installed?
- Whether your heating and cooling ductwork has been insulated – would you even know where to look?
- Whether the windows chosen have the correct minimum U-Value and SHGC
- Whether the underfloor insulation has been included
- The size of the fans
- The correct installation of the wall insulation
- and so on
How big a problem is this?
Like we said earlier, employing a builder usually involves a large element of trust, but is this trust justified?
In 2013, the State government funded National Energy Efficient Building Project (NEEBP) commissioned Pitt & Sherry and Swinburne University of Technology to undertake a national review of key systemic or process weaknesses or points of non-compliance with the energy efficiency requirements in the National Construction Code (NCC).
Their report, released late in 2015, found that “most stakeholders believe that under-compliance with building energy efficiency is widespread, implying that buildings in Australia have higher energy use, higher emissions and higher overall costs for building owners and occupants than necessary.”1
The review engaged with more than one thousand stakeholders to look into the systemic weaknesses and widespread non-compliance regarding energy efficiency requirements of the National Construction Code. It found “a very large number of concerns” and that “many of those interviewed believe that amidst “a culture of sign-offs” and a lack of oversight and enforcement, non-compliance is rife across the entire building supply chain.”2
Around the same time, the CSIRO’s “House Energy Efficiency Inspections Project” found that while the NatHERS software is based upon certain levels of air-tightness in a home in a given hour, the houses that were examined post-build didn’t meet expectations . Over one hundred houses around Australia were examined and tested with thermal cameras and blower door testing to see if the insulation and gap sealing around doors and windows was properly installed and maintained. The results showed that while well-sealed and well-insulated homes were possible, most homes had average air-change measures that were just outside the range of what the NatHERS software assumed. This means that most homes in the study were actually performing worse than predicted in terms of thermal comfort and efficiency, costing the occupiers more in heating and cooling costs.
What can I do?
On a legislative level, the reports agree that more work needs to be done in ensuring that homes are built according to the Energy Efficiency measures that were signed off on before the homes were built. This could involve more inspections of homes, higher penalties for non-compliance, or mandatory post-build assessments of the Energy Efficiency elements in a home.
For the home-owner, knowledge is power. So it is definitely worth reading around sites like this to make sure you understand the elements that go to making up your Energy Efficiency Assessment. Many volume builder clients will not even see, let alone understand, the Energy Efficiency Rating that their home has been given. But it is worth asking for the report, reading it, and making sure you understand it. A NatHERS Certificate from an Accredited Assessor willl look something like this:
Before your contractors receive their final payment, make sure that you are satisfied that all the elements listed on the Energy Efficiency Report are in place in your home. If you feel out of your depth, you can engage the services of a Energy Efficiency Inspector who can give you the assurance that you need in this area. They will charge between $150 and $500 to inspect your home, but in many cases, this is going to be more than offset by your savings in electricity and gas charges over the next ten years.
For further information, please get in touch with us at BERA.