Residential Insulation


Energy prices in North America came into sharp focus in the mid 1970's when the Organization of Petroleum Exporting Countries (OPEC) instituted an oil embargo, greatly reducing production and availability of petroleum products.After World War II, North America had become overly reliant on high quality cheap crude oil from the OPEC nations, and we let our regional exploration and production slide.

The short-term consequences were powerful; a shortage of gasoline and other petroleum products occurred almost overnight. There were long line-ups at gas stations and prices skyrocketed. There was a lot of economic pain for consumers as home heating costs escalated and a lot of pressure on our politicians to do something; and so changes were put into motion.

Governments began to encourage North American oil exploration and production, automobile manufacturers produced more efficient vehicles, and the building industry responded with more energy efficient buildings.

Now, with climate change and steadily rising energy costs, the urgency to reduce consumption is high. Virtually all energy costs are rising; the reasons are myriad and range from scarcity to political conflicts. All we really need to know is that this has been a persistent trend for several decades and is unlikely to improve in the near future. Technology may eventually come to the rescue with energy being sourced through renewables, but meanwhile we have bills to pay. This article will discuss residential insulation as a means to reduce energy consumption and, thereby, your energy costs.


We can start by talking about the present standards for insulation in newly built homes. These standards vary somewhat from province to province, but generally follow the criteria established in the National Building Code; an ever-evolving document. Changes to the building codes are driven, in part, by a need to reduce energy consumption and, in the face of climate change, reduce our carbon footprint.

This will not be a technically exhaustive discussion but should give you enough information to confidently discuss the subject with a qualified builder or insulation contractor.

"R" Value

You may have already heard people talk about "R" values as they relate to insulation standards. The "R" refers to "resistance" to heat loss."R" values vary depending on the materials used to create an air break between the interior and exterior of a home. The air break is essentially dead air trapped in the insulation material. That dead air does not allow heat to easily transfer from the warm interior to the cooler exterior; the higher the "R" value, the greater the resistance to heat loss.

The greatest heat loss, like your head, is via the top of the home. The house, like you, needs a "hat" to retain the home's heat.So the home's highest "R" value is in the attic, on top of the uppermost ceiling in most cases.The present standard calls for R-60.

We also have to insulate the exterior walls of the home. Like a jacket that keeps you warm, the insulation holds in the home's heat.Above soil grade, the present "R" value for exterior walls is established at R-22, and for foundation walls below grade, R-20.


There are several insulation materials in common use in newly built homes. A short list of the most common materials includes glass fiber (fiberglass), cellulose fiber, spray foam, and plastic board insulation (polystyrene - also known as styrofoam).All or some of these materials may also be found in many older homes where the insulation can also include the presence of vermiculite, seaweed, and rock wool.If you are anticipating an upgrade to your home's insulation, you will turn to the more modern materials for a retrofit.

Some of these materials come in batt form, board form, loose fiber, and spray foam applications. An experienced insulation contractor can advise you with respect to which type of insulation application is appropriate for any particular use.The important thing is to achieve the desired "R" value within your available budget.Some provinces offer grant/rebate programs to help offset the cost of energy saving upgrades.

As you might imagine, different materials present with varying "R" values, and therefore need to be installed in thicknesses that meet the requirement at hand.A rough guide to "R" values per inch for various materials looks like this:

  • Fiberglass – 2.0 - 4.2 (loose fill, batts, rigid)
  • Cellulose fiber – 3.4 - 3.6 (loose fill)
  • Plastic board – 3.7 – 6.0 (rigid board)

Variations in similar material can relate to density. To determine how many inches you need for a particular application, just divide the desired "R" value by the "per inch" value. For example, an attic requiring R-60 using cellulose fiber will need roughly 17" to 18" of depth (60/3.5).


Various insulation materials have properties that lend them to specific uses, and not to other uses.

For example, loose fiber insulation (cellulose or fiberglass) is not the best application for walls as it will, over time, due to gravity and vibrations, settle. This will create insulation voids and cold spots in the wall. You will lose energy at these cold spots, and you may experience surface condensation in the winter. Fiberglass batts, plastic board, and/or spray foam insulation are best for walls because they will retain their shape.

Cellulose fiber will absorb and retain water and should not be used in areas where water incursion or dampness may be an issue. This would be especially true of basements and crawlspaces.

The interior use of plastic board insulation, because it is a flammable material, requires a fire break between the living space and the insulation.This usually takes the form of a layer of ½" drywall.This may also be necessary with some types of spray foam insulation.

Seek the advice of a qualified insulation contractor before purchasing material to upgrade your insulation.For more information, please visit, NAIMA Canada for incentives and rebates.

Older Homes

If you own an older home, built prior to the mid 1970's, the insulation standards were very low.There is room for improvement though, most notably in the attic where it easier to add insulation on top of the existing layer(s). However, it is more difficult to add insulation in the exterior walls as these are enclosed spaces. These homes were typically framed with 2x4 wall studs, so conventional fiberglass batts can only create an "R" value of R-12 at best. You can add rigid insulation to the walls if you replace the original exterior cladding with new siding, but be careful to use methods and materials that do not trap moisture in the wall cavity.

And, if your home is more than ten years old, there is probably still room to improve your insulation to resemble the present standards more closely.Again, the most obvious place to add insulation is the attic.

Energy Audits

There are presently rebates and grants available to help you afford an energy assessment of your home. The information gained through this process will help inform decisions about insulation upgrades and other measures to reduce energy costs in your home. Those measures can also attract rebates and subsidies from various governments.The energy advisor will be able to provide precise information that applies to your specific community.For more information, please visit, The Canada Greener Homes Initiative.

If You Build A New Home

There are many new building methods and technologies emerging all the time. Insulated concrete forms (ICF) have been around for a few decades now but are gaining in popularity as more builders become familiar with the product range.ICF creates concrete walls sandwiched between two layers of rigid polystyrene (styrofoam) insulation. It can be used to create just the foundation walls, with conventional framing on top, or you can build all of your exterior walls with ICF. This makes for a very strong structure with a great sound barrier and outstanding insulation values.ICF though, is just one of many new technologies available.

Heat pumps, solar assisted water heating, solar electric panels, high efficiency appliances and more can reduce your home's carbon footprint and save you money over the duration of your ownership. Insulation is a great place to start your energy saving journey, but don't stop there. Take advantage of the information available from home inspectors, builders, and credible media platforms to build a better future.

Modern Roofing Trends
January 31, 2023
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