The R-Value of Insulation:

As winter is arrives, we all know that a decrease in outside temperature means an increase in your home heating costs. Fortunately for us there are some easy steps that you can take to save money. The first step is to understand how your home functions in terms of heat gain and loss.

Your home is made up of a variety of materials, brick, glass, wood, and insulation, each having it’s own R-value. An R-value is a measure of a material’s resistance to heat flow. R-value is connected to the effectiveness of the house’s insulation. Therefore the higher the R-value, the warmer you will be this winter.

Here’s how it works. Heat flows naturally from a warmer space to a cooler space. In the winter, this heat flow moves directly from all heated living spaces to adjacent unheated attics, garages, basements, and even to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors—wherever there is a difference in temperature.

In order to maintain constant comfort this winter, the heat lost through large north facing windows, or by inadequate attic insulation must be replaced by your heating system. Properly insulating your home will decrease the amount of heat lost by providing an effective resistance to the flow of heat.

Insulation's resistance to heat flow is rated in terms of its thermal resistance or R-value. Where glass has an R-Value of 3, high-density fiberglass batts for insulating standard stud-framed walls are rated at 15. With a simple experiment of placing one hand on your window and the other hand on an interior wall you will notice the extreme difference in temperature between the two surfaces.

Things to remember. The R-value for house insulation decreases significantly when there are air or water/moisture leaks. Also, the standard R-value for house insulation varies based on climate and temperature. Some of the best and most readily available insulation materials include: fiberglass insulation at an R-value of 3.1 per inch, blown in cellulose insulation R-valued at 3.7 per inch and expanded polystyrene which is rated at 4 per inch. If you are looking for a more natural alternative, visit Now, when looking to increase the R-value of your windows, ensure that existing window frames are properly sealed. If replacing a window, look for one that has Low-E glass (low emissive), which reduces energy transfer (heat and ultraviolet rays). Following these simple steps will draw you closer to a high efficiency, low cost home.

For more tips and information visit Natural Resources Canada at

This article was prepared by the Burlington Sustainable Development Committee. 

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