Windows 104 - lowE... not sure?

Double-glazed lowE windows letting the valuable winter sun in.

If you are designing a home to solar passive principles for Canberra’s climate (with a really well insulated and sealed building envelope), it often makes good sense - thermally and financially - to install double glazed windows with a high solar transmission lowE coating. The lowE coating adds an insulating layer which increases the energy efficiency of your windows by reducing the transfer of heat or cold through the glass.

The sun’s energy comes into your home through the windows as short wave radiation (light). It is absorbed by objects such as the flooring and furniture, which transforms it into long wave radiation (heat). The heat then wants to flow from warm areas (inside your home) to cool areas (outside). However a high solar transmission lowE glass will reduce the amount of heat escaping through your windows and reflect it back into the room.

We use thermal performance (EER) modelling on our house designs to ensure the energy efficiency measures we recommend to clients offer good "bang for buck" for their particular design in our particular climate.

Using EER modelling Jenny decided to use high solar transmission lowE coating on all the windows in her new house. However in her previous reno she chose to use it only in the living areas. Costs have come down since her reno and it had a bigger thermal impact in the new design.

We encourage everyone to use the EER modelling, that is required for most new builds, as an opportunity to ask their energy assessor to assess the thermal impact of different types of glazing on their house design.

Windows can have a significant impact on the heating and cooling loads of your home. Between 46% - 61% of a home’s heating energy can be lost and between 79% - 86% of its heat gained through windows. So, it’s important to make informed decisions about the types of windows and glazing you need in your home.

You can learn more about lowE glass here.