Your guide to U-Factor, R-Values, ER Rating, SHGC

When making decisions regarding home improvements, it is crucial that consumers understand the benefits that each product can provide to the efficiency of their home. There are many ways to measure the efficiency of windows and doors performances. What should you choose when it comes to the different values? Let us start by first understanding the terms and what they measure:

Energy Rating

The energy rating of window and door products is based on the performance of the fenestration systems (windows, doors, skylights) and is independent of the material used. The ER (Energy Rating) is determined by three factors: heat loss, air leakage, and potential solar gain. The ER number comes from balancing these three factors in a formula where the outcome is the energy rating, a unitless value. Energy Rating is used to rate fenestration systems that are intended to be installed in a vertical orientation in low rise buildings. When choosing your windows based on ER compare the same window types because ER changes depending on the operation of windows. For example, fixed windows have a higher energy rating because they do not open resulting in decreased air leakage and heat loss.


When measuring the heat transmission of an element required for building, specifically applying to windows and doors, the U-value indicates the insulation efficiency of the material. Essentially, a lower number means that the insulating properties are better. By analyzing different necessary components required for the installation of the window or door, such as material, weatherstripping, panes, and caulking, the calculation is then able to reflect the energy efficiency and ability to conduct heat. Based on these ratings, consumers can choose the windows that best suit their needs. To maintain the desired temperature within the home, the windows must be energy efficient meaning minimal heat transfer; this would be reflected by a low U-value.


Similarly, the R-value is a tool used to measure the resistance of heat flow within a material, a larger number means that heat is not easily transferred. This calculation represents the ability to prevent heat loss; this considers materials, caulking, weatherstripping, insulation, coatings, and the presence of windows within doors. For the most energy efficient options, consumers must look for the highest R-value to obtain the most effective products.

Solar Heat Gain Coefficient (SHGC)

The SHCG is a value between 0 and 1 representing how much heat in transferred into the home through the window from the incidents of solar rays, 0 meaning no heat was transfer while 1 means a large amount of heat was transferred.

WD CRAFTLINE offers expertise in supply and installation in upgrading your window and doors across Ontario. Our seasoned installers help our customer to transform their home with minimum disruption through their days. We offer products that is qualified for the greener home rebate and budget friendly payment options.

Our friendly consultant will review your existing window operation, design and provide valuable recommendation base on your style and budget needs. We take pride in the wide range of product selections and window installation. Our goal is to make your home look and feel beautiful at a competitive price with windows and doors that delivery long term value in years to come.

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WD Craftline offers a spectrum of product lines that will satisfy the likes of budget conscious homeowners, to the most prestigious, particular and visionary builders and designers. Selections ranging from simple and understated, to the very highest end of innovative upgrades and luxury features. Craftline offers it all.

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761 Main St. E, Unit 2
Milton, ON, L9T 3Z3


7250 Keele St, Unit 156
Vaughan, ON, L4K 1Z8

1-(844) 980-1778

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