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    • Life Cycle Assessment
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Why are windows & doors important and how do you make the right choice?

Choosing the right windows and doors has a significant impact on heating and cooling bills, as well as on maintenance.

  • Windows & Doors open the space and provide magnificent views.
  • provide the opportunity of controlled ventilation.
  • contribute to the look of the building.

Aside from the aesthetic appearance of the window and door there are a number of performance measures that will determine the comfort and energy consumption of the window or door in use.

Choosing and comparing windows & doors you should be prepared to ask the right questions and more important be able to evaluate the quality of the answer.

“I don't want my window to be a thermal wound or thermal flaw in my building, seriously”

49% of heat loss of a building is through the windows and doors.

87% of solar gain of a building is through the windows and doors.

What are the important factors for you when choosing windows & doors?

Design & Appearance

  • Do you have the freedom to customise the windows & doors – the sizes, shapes, glass, colours and extras (e.g. handles, locks etc.)?
  • Does the design influence the performance of the window?

With Miglas products you can individualise the look of your home. Develop an eye catching house front and achieve a perfect balance with your overall building design.

Tip: The design options should give you the freedom to choose without influencing the performance.


  • What are the costs over the life cycle – maintenance (e.g. painting) and energy (e.g. heating & cooling savings)?
  • What is the life expectancy of the product?

Keep in mind that windows & doors usually remain in your house for over 25 years. They are an investment and you should check the value over time.

Don't forget to check the constancy of the performance as cost factor – quality hardware and seals should ensure a long life expectancy.

Tip: Ratings show you the performance of your new product. They don't necessarily incorporate the quality of hardware and gaskets for ongoing durability. Check the hardware and seals for functionality.
The best way is to touch and see.


  • How is the window rated?
  • How does the window perform over its lifetime?
  • What are the performance measures that show the value of the product?
  • What is the life expectancy of the windows?

The discerning customer will invest in quality windows.

As well as performance, maintenance and handling you should always consider the environmental impact of your choice.

Tip: The rating is just a snapshot in time. Always ask for the value and constancy of the performance over time. Including various aspects in your decision is important. The bitterness of poor quality lingers on long after the sweetness of a low price.

Do I need double glazing?

The BCA (Building Code of Australia) requires certain energy ratings in each region when you build a new home. These standards are expected to apply for every home in Australia in the future and the criteria will be more detailed in the future.

Tip: Only double glazing offers a convenient comfort and security level all year round.

Is double glazing enough?

Double glazing is only one component that contributes to the performance. The frame, gaskets and hardware as well as the level of craftsmanship influence the quality of the product

Tip: Windows and Doors are a long term investment – see & touch the whole product before you make a decision.

Is it easy to compare windows?

The performance measures are a good indicator, but they only show a fraction of the window quality level. Sustainability of components, value over life cycle and functionality are not represented by generalised values & ratings.

Tip: You really should make sure that you compare apples with apples. In the WERS rating tables you will find a lot of windows that are nowhere near a real application. E.g. 0 Air Infiltration usually means a solid pane of glass and no chance of natural ventilation of your choice.

Are performance values important?

The performance measures should be your minimum requirement, but always check if they apply for the whole window (not just for one component) and if its applicable in real life. The Rating (WERS) is a computer simulated testing. In regard to the frame the system disadvantages timber to aluminium. This leads to inaccurate and distorted values.