Frequently Asked Questions  

Welcome to our page of Frequently Asked Questions. This page is a work in progress as we are always being asked new questions - which we are always happy to answer. If you have a question / inquiry about the energy rating process or the work that Sustainability House does please email us HERE or call 1300 308 525 


How do I get a 6 star House?

A 6 star house can come in many shapes and sizes, but it is worthwhile noting that as houses increases in size it can become harder to obtain 6 stars or higher. 

Most homes that easily obtain 6 stars will be well orientated, with good northern access for solar gain in winter and shaded in summer with appropriate eave widths. They will have a reasonable window to floor area ratio and will have good insulation to the external walls and ceiling. 

More problematic dwellings that do not so easily obtain 6 stars may need increased levels of insulation, improved window systems and in some cases minor redesign. Depending on the design, Sustainability House may recommend other methods of assessment to allow the dwelling to pass the National Construction Code (Building Code of Australia). See our section on BCA Consulting for more information. 


What do I need to send you to have the project assessed?

Encourage use of client access system. Link YouTube client access system

Depending on the project there are several key documents that we will need in order to be able to undertake an assessment, these are:

  • Site plan with north point 
  • Floor plans
  • Elevations
  • Electrical plan (for services assessment) 

Highly desirable documents include:

  • Window schedule 
  • Section drawings 

We have a couple of straight forward forms to capture all the information about the project - and if you are not using the Client Access System 


What if I don’t have defined specifications?

That's ok! Often Sustainability House will be asked to assess basic plans and for these include all the necessary specifications (eg: insulation / glazing) in order to get the home to pass. Generally we will look at a least cost path to compliance and will always consult with our customers about what the options are. 


Why is so important to have northern glazing?

Northern glazing plays an important role in keeping the home comfortable in winter. In the colder months we want to encourage as much solar gain into the building during the day, especially if we have internal thermal mass such as a polished concrete slab floor or internal mass walls that can absorb the suns energy and release this at a night time helping to warm the house and maintain a comfortable internal temperature. It is important to note that northern glazing needs to be shaded in the summer months so as to exclude that heat energy - appropriate eave widths, shading devices or vines growing are all strategies to mitigate summer solar gain. 


Why does my whole house have to be assessed when I’m only getting an extension done?

Often with a house extension it is difficult to achieve stand-alone energy efficiency compliance without including the whole of house into the equation. This is primarily due to the nature of modern design that we see in extensions where there is a large window to floor area ratio and open plan living areas within a relatively small footprint. By undertaking a whole of house assessment the existing home can be factored into the overall energy rating allowing a better understanding as to how the extension will perform. It is worthwhile noting that when undertaking building work to the existing home there are good opportunities to update and improve the existing home - for example re-insulating the existing and proposed to the same level or making key choices to update glazing. 


We are planning to build, do you have a service that can give us advice on solar passive design before we decide on house design

There are some general rule-of-thumb principles that can be adhered to when designing with passive solar design in mind. Having northern glazing, thermal mass, well sealed windows, shading in summer, passive ventilation options and the ability to night purge the house are all key considerations. The Your Home Manual offers a number of guides - worth reading! 


Why do I need an assessment done?

Part of the compliance framework for new building work is to ensure that homes meet energy efficiency standards are expressed in the National Construction Code (Building Code of Australia). The energy efficiency standards are designed to lower greenhouse gas emissions that are associated with climate change and hence the impact that building work has on the environment. 


Where can I find an accredited assessor?

Sustainability House are an accredited assessor. We are members of the Building Designers Association of Australia (BDAV) who are an accrediting body. 


How can I improve on my house/design and keep cost down?

Depends on the design. Orientation of the building and positioning of living spaces is one of the key concerns. Generally we would be looking at the amount of glazing that is in the dwelling and the type of glazing used (eg: whether it is improved to double glazing etc). Shading is another key element - paying particular attention to the northern aspect of the building. 


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By using industry leading best practices, Sustainability House can strategically assist in delivering cost effective solutions to energy efficiency issues, whether you are building a new home or a major commercial project.

HIAMaster Builders AustraliaBuilding Designers Association VictoriaGreen Building Council

Australia's leading Provider of Energy Efficiency Modelling Services to the Construction Industry

Assisting builders, developers, architects and designers right across Australia

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