Energy Saving Caluculation

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Energy Saving Calculation: My name is John Finlay, I am a House Energy Rating Assessor registered with Planning SA and recognised as an Independent Technical Expert under Regulation 85 for the purposes of regulation 88 of the Development Regulations 1993.

What Are The Benefits Of A Higher “Energy Star Rated House?”

  • Reduced Energy Consumption to heat or cool the house
  • Minimal Cooling/Heating during short run extreme weather conditions
  • Less stress on internal furnishings and less food spoilage due to more stable internal temperature
  • Lower Energy Bills
  • Lower Carbon Footprint

Comparison Between Different Energy Star Ratings
In the Adelaide Climate Zone, The Star Band Energy Consumption is:

  • 3 Star = 227MJ/m2 ( MJ/m2 = Mega Joules per square metre)
  • 4 Star = 165 MJ/m2
  • 5 Star = 125 MJ/m2
  • 6 Star = 96 MJ/m2
  • 7 Star = 70 MJ/m2

The Energy Star Rating increases as less energy is needed to heat/cool the house.

If you live in a 3 Star house you would need over three times the energy for cooling/heating to obtain the same comfort as a 7 Star house!
Most houses in Adelaide are between 3 and 4 Stars, so there is significant savings to be made by purchasing a higher energy rated house.

What is The Maximum Energy Star Rating?
The maximum is Ten (10) Stars. A 10 Star energy rated house would not need any heating or cooling!

How Is The Energy Star Rating Calculated?
These calculations were created by the C.S.I.R.O. The computer software calculates the estimated heat load every hour of the day for a year based on weather data, the desired internal comfort temperature and house orientation.
Movement of people, kitchen use, lights and opening windows and doors are also taken into account in the calculations.

How Does This Energy Star Rating Calculation Relate To Greenhouse Gasses?

  • Australia produces 550 million tonnes of greenhouse gasses in total.
  • 20% of this is attributed to houses, totalling 110 million tonnes.
  • Heating and cooling is approximately 38%, which represents 42 million tonnes.

If all houses had 7 Star Energy Ratings, we could easily more than halve the 42 million tonnes of Greenhouse Gasses and be more comfortable and wealthy!

Dollars & Cents !

The average energy use in South Australia for household heating and cooling is 36%
Source: Government of South Australia Department for Transport, Energy and Infrastructure.
Example: Moving from a 3 Star home into a 7 Star home = 70 /227 = 31% (approx)
Assuming that your quarterly energy bill is $500, then 36% of this bill is due to heating and cooling in South Australia.

Bottom Line: Cost of heating/cooling:  $500 x .36 = $180, therefore, Your heating/cooling cost may reduce to 31% of the $180 = $55

*Possible Saving on this example: $180 – $55 = $125 per quarter or $500 per annum. The introduction of carbon emissions trading will no doubt see the cost of energy rise considerably over the coming years.

*This Energy Saving Calculation is generated by the Seven Star House itself, and does not take into account the extra saving generated by the inclusion of:

  • 1.5 kw Solar Electricity
  • Solar Hot Water
  • 9,000 Litre Rain Water Tank