Is a 7 star house good enough for Australia?
Compared to other developed countries, how does the insulation standards of Australia compare? Developed countries encourage/enforce rigid exterior insulation. Their standards are about 10 or more time higher than that of Australia in most cases.
7-STAR HOMES
The Monk
5/8/20242 min read
In Australia, the energy efficiency of residential homes is rated under the Nationwide House Energy Rating Scheme (NatHERS). A 7-star rating means the home is designed to maintain a comfortable indoor temperature throughout the year with minimal need for additional heating or cooling. This rating takes into account the building’s design, orientation, insulation, and thermal mass, aiming to reduce energy consumption and environmental impact.
In terms of comparison:
Europe: Many European countries use the Energy Performance Certificate (EPC) system, which rates homes from A (most efficient) to G (least efficient). A 7-star NatHERS rating is roughly equivalent to an EPC rating of A or B, indicating high energy efficiency.
United States: The Home Energy Rating System (HERS) Index is commonly used, where a lower score indicates better efficiency. A typical new home is rated at around HERS 100. A 7-star NatHERS home would likely have a HERS Index in the range of 40 to 60, meaning it uses about 40% to 60% of the energy of a standard new home.
Canada: The EnerGuide system provides ratings out of 100, with higher numbers indicating better energy performance. Homes built to meet the latest standards typically score between 70 and 80. A 7-star NatHERS rating would correspond to a similar score range, indicating good energy efficiency.
Japan: Japan uses a rating system that measures energy consumption per square meter. Homes are rated from 1 star to 5 stars, with 5 stars being the most efficient. A 7-star NatHERS home would likely align with a 4 to 5-star rating in Japan, demonstrating high efficiency.
The R-values, which measure thermal resistance, vary depending on the building codes and climate zones within each country. Here are some typical R-values for walls, ceilings, and floors in the mentioned countries:
Several countries enforce or strongly encourage the use of external rigid insulation, particularly in regions with strict energy efficiency standards and building codes. Here are a few examples:
Having seen that, can you guess what is the thermal resistance value for a 7 star property in Australia
Walls: R-2.5 to R-3.5
Ceilings/Roofs: R-4.0 to R-6.0
Floors: R-2.0 to R-3.0 (if insulated)
Is this good enough for Australia? What do you think, let us know.
