When preparing a window quotation for a new home, we always ask for two things:

  • A Window Schedule, used to determine the shapes and sizes of each window, and
  • An Energy Report.

The Energy Report contains a section regarding glazing requirements, to ensure that maximum energy efficiency is achieved. Energy efficient windows can dramatically reduce your energy costs by significantly minimizing heat gain in summer and heat loss in winter, all while lowering your emissions and reducing your carbon footprint.

There are two very important terms that we look for in the Energy Report, and they are the “U-value” and the “Solar Heat Gain Co-efficient (SHCG)”.

The U-value measures how well a product prevents heat from escaping. The lower the U-Value, the greater a window’s resistance to heat flow and the better its insulating value.

SHGC measures how well a product blocks heat caused by sunlight. The lower a window’s SHGC, the less solar heat it transmits.

We then take the two measurements, and cross-check them on a Performance Data Table (pictured below with an example), which tells us exactly what type and thickness of glass we need to use in order to meet the two values.


Why is it important for you – the customer, to understand these terms?

For two reasons.

One – Glass is the most expensive element of a window. The type, and thickness of glass that is used will determine the price tag that comes with your windows. The higher performance rating you want to achieve, the more expensive the glass becomes.

And, two – it is important to ensure that your windows are as energy efficient as possible. Not only will it save you money in the long term by reducing your energy bills (you can switch off that heater or that air-conditioner!) but it also helps us strive toward a greener future, by reducing emissions.

If you are budget minded but also want a high-performance glass, chat to us about what the best options would be for you!