Thermal Performance

Is your builder 6-Star ready?

Building your new 6-Star home is an exciting journey and you may have a lot of questions. Therefore it’s important to choose the right home builder to help guide you through the process.

But how do you choose the right one?

Start with the following list of questions. Make sure you ask these questions upfront, to avoid finding out important information once it’s too late.

• How long have you been in the industry?
• What experience do you have with sustainability?
• Do you have 6-Star designs already?
• Can you design a home to suit the orientation of my block?
• How long will it take you to rate my home’s energy efficiency?
• Are you implementing 6-Star from 1 May 2011?

Also, keep an eye out for builders who have won awards for sustainable building design. This shows they are proactive in building sustainable homes, and can share their knowledge and experience with you.
Of course you will always be able to include your personal touches. Discuss your needs and compliance with the 6-Star requirements with your builder.

What is the Assessment Process?

The new 6-Star regulations will require greater stringency of the Building Code of Australia’s Deemed-to-Satisfy (DTS) requirements, meaning in most circumstances builders will find it easier and cheaper to obtain professional compliance advice from an energy efficiency assessor. Importantly, this assessor MUST be accredited under the Nationwide House Energy Rating Scheme (NatHERS).

Your assessor will utilise computer simulations to determine a home’s level of thermal comfort. This is achieved by considering multiple aspects of the home including its layout, window and shading orientation (in regards to the local climate), and the construction of its roof, walls, windows and floor. When all features have been considered, the assessor has the information needed to determine the home’s rating. This process will also uncover cost-effective ways to optimise energy efficiency, helping home’s to obtain full building compliance by securing a greater rating.
As you would expect, it’s much easier and more cost effective to increase a home’s energy rating at the design phase. Therefore, it’s important to engage your accredited assessor early so that they can have input at the design stage of the home. That way, the home can be built with confidence knowing that it meets the requirements and won’t require last-minute alterations.

How do you achieve a 6 Star home?

Achieving a 6-Star rating is the culmination of numerous design elements working together for the right climate zone.

Here are just some suggestions that can increase a home’s star-rating:

• Consider the home’s location, and how it is orientated on the block.
• Place non-habitable rooms such as laundries and bathroooms to the east and west, bedrooms to the south and main living rooms such as dining and meals to the north.
• Keep size in mind, as the bigger the home, the more difficult it is to get higher star ratings.
• Purposefully minimise wall area by avoiding complex floor plans that can increase the external wall area.
• Maximise north windows and minimise western, southern and eastern windows. Minimise window glazing on eastern and western windows.
• Plan proper shading for windows.
• Choose a flued gas heater instead of gas negus points.
• Increase ceiling insulation to R4.
• Consider wall cavity insulation, target east and west facing walls.
• Consider floor treatments such as floor tiles to living areas.
• Utilise ceiling fans.
• Choose energy efficient lighting, including use of sensors.
• Identify areas that can be ‘zoned’ or closed off.
• Seal doors, windows, vents and exhaust fans (self-sealing exhaust fans are an option).
• Consider tinted or double-glazed windows.
• Consider outside colour (roof and walls).

If you have already selected a block, your builder should offer a number of houses that are already 6-Star to suit the orientation and ‘climate zone’ of your existing block.

If you have not already chosen a block, your builder can help you choose a block with an orientation that best suits your favourite home design and optimise your overall energy rating.

Passive Design

Passive design is design that does not require mechanical heating or cooling. Homes that are passively designed take advantage of natural climate to maintain thermal comfort.

Incorporating the principles of passive design in your home:

Significantly improves comfort
Reduces or eliminates heating and cooling bills
Reduces greenhouse gas emissions from heating, cooling, mechanical ventilation and lighting.
Building envelope is a term used to describe the roof, walls, windows, floors and internal walls of a home. The envelope controls heat gain in summer and heat loss in winter.

Its performance in modifying or filtering climatic extremes is greatly improved by passive design.

Well designed envelopes maximise cooling air movement and exclude sun in summer. In winter, they trap and store heat from the sun and minimise heat loss to the external environment.

The fundamental principles of passive design, explained above are relatively simple and can be applied to the various climate zones, house types and construction systems in Australia.

Energy Efficient Home Ideas

For most people, the place where you have the most opportunity to make choices which will save you energy- and money- is in your home. There are many things to consider, each one taking you a little further in your quest for energy efficiency.

Insulation is one of the best ways of lessening the amount of energy you need to use in heating and cooling your home. Different insulation materials have different ratings, so before taking up just any insulation offer, look into what they are offering.

Energy use can be cut by having appropriate windows and their ‘dressings’.
Blinds can keep out heat, or cold, and can be used to shade walls too, not only windows.
Heavy, thermal curtains keep the exchange of temperature with the outside at a minimum.

Ventilation is an important aspect of creating an energy efficient house. It can help release hot air to the outside and also move cooler, or warmer air through the house to stabilise the temperature.

Ideally you would have engaged a thermal performance assessor from the planning stage of your project.

6 Star Design Advantages

Rate Energy encourage clients to plan with this in mind, this is the most cost effective way or achieving 6 stars or the required star rating.

You can achieve the 6 Star Standard with a few simple adjustments to design and construction, and by including a combination of the many options to improve the building’s energy-efficiency, such as:

Orientation: passive solar design
Draught-proofing and sealing of the building’s envelope
Better window design (including size, location, quality thermal performance of frames and glazing)
Building fabric (including selection of cladding materials, flooring).

The same passive principles apply of maximising cooling air movement and excluding sun in the hot months, trapping and storing heat and minimising heat loss to the external environment in cooler months.

A variety of dwelling types encourages diversity in the social mix and offers multiple design opportunities for different sustainable strategies.

Six Star Energy Rating

Your new home design will be assessed using the latest FirstRate5 version software and a 6 star + rating achieved. Should your design not achieve the 6 star rating required, options will be offered until we achieve the desired results.



Highly humid with a degree of ‘dry season’.
High temperatures year round.
Minimum seasonal temperature variation.
Lowest diurnal (day/night) temperature range.


High humidity with a definite ‘dry season’.
Hot to very hot summers with mild winters.
Distinct summer/winter seasons.
Moderate to low diurnal (day/night) temperature range. This can vary significantly between regions eg inland to coastal.


Distinct wet and dry seasons.
Low rainfall and low humidity.
No extreme cold but can be cool in winter.
Hot to very hot summers common.
Significant diurnal (day/night) range.


Distinct seasons with low humidity all year round.
High diurnal (day/night) temperature range.
Low rainfall.
Very hot summers common with hot, dry winds.
Cool winters with cold dry winds.


Low diurnal (day/night) temperature range near coast to high diurnal range inland.
Four distinct seasons. Summer and winter can exceed human comfort range. Spring and autumn are ideal for human comfort.
Mild winters with low humidity.
Hot to very hot summers with moderate humidity.


Low diurnal (day/night) temperature range near coast to high diurnal range inland.
Four distinct seasons. Summer and winter can exceed human comfort range. Spring and autumn are ideal for human comfort.
Mild to cool winters with low humidity.
Hot to very hot summers, moderate humidity.


Low humidity, high diurnal range.
Four distinct seasons. Summer and winter exceed human comfort range, variable spring and autumn conditions.
Cold to very cold winters with majority of rainfall.
Hot dry summers.


Low humidity, high diurnal range.
Four distinct seasons. Winter can exceed human comfort range.
Cold to very cold winters with majority of rainfall. Some snowfall.
Warm to hot, dry summers, variable spring and autumn conditions.