>   Blog   >   U-Value & SHGC Explained
U-Value & SHGC Explained

Often new homes and buildings are required to meet a certain energy rating or star value. In order to achieve this rating our aluminium windows and doors need to comply with certain performance values for energy efficiency. The terminology that we use to describe these performance values is known as Uw Value and Solar Hear Gain Co-efficient (SHGC).


The U-value measures how well a product prevents heat escaping through the whole window (frame and glass). It does not factor in solar heat from direct sunlight. The lower the U-value the better the insulation properties of the aluminium window i.e., the better a window is at keeping the heat or cold out. To comply with energy rating reports U-values must be equal to or lower than specified. Generally U-values in Australia fall between 2.0-10.0 W/m2.K.


SHGC is a measure of how much solar radiation passes through a window or door. The lower the number the less solar heat it transmits. Windows that have a high SHGC allow a greater amount of solar radiation which will heat up your home or building quicker. To comply with energy reports the SHGC must be within 10% of the set value. SHGC is expressed as a number between 0 and 1. The type of glass selected (laminated, toughened, tinted etc.) can greatly affect the SHGC rating.

Due to the number of glass and window combinations we cannot show you all of the ratings here, but if you would like to know more it’s best to contact us as navigating the WERS website for ratings is difficult if you don’t know what to look for.climate_map

  • 26 February 2015
post by Jerry
call us(03) 9792 0083