According to the National Construction Code, a 6-star energy efficiency rating is the minimum requirement for all new residential homes in Australia. Because of this, homeowners and building designers must plan strategically to ensure that a new home is as energy efficient as possible.
This rating is given by the Nationwide House Energy Rating Scheme (NatHERS). It uses a scale of 0-10 and reflects the amount of energy a property uses for heating and cooling purposes. A household with a low rating will have to use their A/C unit frequently to go through heating and cooling cycles. On the other hand, a home with a 10-star rating can theoretically regulate temperature with little to no use of air conditioning. Essentially, the less energy a home uses, the higher the rating.
So, how do you achieve a 6-star rating? How is energy efficiency assessed? To help you answer these questions, we’re going to have an in-depth look at what 6-star energy rating entails. We will discuss the assessment process as well as the factors you need to consider.
How is it assessed?
A home’s energy efficiency can be evaluated by one of NatHERS’ Accredited Assessors. These energy assessors are professionally trained to conduct quality inspections and follow the Assessor Code of Practice. To ensure that your home passes the 6-star minimum, it is recommended that you consult an Accredited Assessor in the early stages of your home’s planning and construction.
There are plenty of variables that go into your home’s energy efficiency. Therefore, NatHERS Accredited Assessors will have to assess various aspects of your home including:
- Materials and construction: Assessors will be checking the type of insulation that you have as well as the placement and size of your vents and ceiling fans. They will also check if you have insulated glass units (IGUs).
- Geographical location: Homes in Tasmania will typically endure much colder temperatures than homes in NT. Because of this, a 6-star rated home in Darwin may not be as energy efficient in Hobart.
- Orientation: Generally speaking, homes that are north or north-east facing are considered to be more energy efficient as they get a lot of radiant heat throughout the afternoon.
Now that you know what will be assessed, here are five tips to help you plan for an energy efficient home. Though most of these tips are simple enough, we recommended working with an energy consultant for the best results.
- Consider the size of your home
The energy efficient features that work in a standard-sized home might not be as effective in a larger home. This is because the bigger your home is, the more energy it will take to heat it up and cool it down. It will also require more insulation materials and more IGUs. If you want to achieve a high-efficiency rating on a large property, it will likely cost more money.
So, when deciding on the size of your home, think if you’ll be able to manage its heating and cooling requirements.
- Install double glazed windows
Double glazed windows are able to trap heat inside your home during the winter and keep it out during the summer. This will take off a lot of pressure off of your air conditioning unit, thus, reducing energy consumption.
The orientation of your windows is also important. North-facing windows will be able to take in a lot of radiant heat during the high-afternoon hours. This means less artificial heating will be needed during the winter. In the summer, you can easily use blinds to prevent the heat from entering.
- Get insulation
Since heat also escapes through your walls, it’s important to choose a good insulation material. This will help your property retain more heat, reducing your dependence on your heaters.
Popular insulation materials include fiberglass, mineral wool, cellulose and polyurethane. Fiberglass is the cheapest option but it has a relatively short lifespan and may contain carcinogenic fibers. Polyurethane, on the other hand, offers high insulating value but it will cost you a lot more.
To find the best option for you, make sure to consult insulation specialists.
- Use sealing
Even after installing double glazed windows and insulation batts, heated or cooled air can still escape through the gaps in your skirting, window sills and door frames.
To improve your home’s thermal performance, these gaps will need to be sealed. Commonly used sealing materials include expandable polyurethane, acrylic-latex caulk and fire-rated caulk.
- Use energy efficient appliances
When assessing your home’s energy efficiency, the Accredited Assessor will not evaluate the efficiency of your appliances. Appliances don’t directly influence your energy rating, it’s still a significant part of being energy efficient. Since the ultimate goal is to reduce our environmental footprint, this is an important point to discuss.
Make sure to buy appliances that have a high energy efficiency rating. It’s going to cost you more upfront, but it offers a lot of economic and environmental benefits in the long run. A/C units with a high energy rating will use less power to heat or cool your home. This reduces your power bills, reduces energy consumption and lengthens the lifespan of the unit.
Hopefully, this gave you an idea of how to design an energy efficient home. Though this blog was about achieving a 6-star rating, no one is stopping you from getting an 8 or even 10-star rating. Go above and beyond and do your part in protecting the planet.