What Are the Insulation Standards in Quebec?

It’s common knowledge that insulating a house will have a significant impact on the overall comfort of the ambient temperature as well as the building’s energy efficiency. While our energy expenses may set us on the right path to knowing whether our home is properly insulated or not, there’s a way more accurate way to find out, and that’s by relying on insulation standards and calculating the energy efficiency of different materials. 

Quebec’s Insulation Standards: A Regulation to Better Oversee Work Carried Out

Source: Canva

Since 2012, the Quebec Construction Code has imposed new standards for matters related to energy efficiency and ventilation. Homes that meet these requirements make it possible for homeowners to significantly save while enjoying better air quality and improved comfort. 

Insulation requirements have been made more stringent, especially for buildings located in colder climate zones. The overall recommended thermal resistance takes into account the combined thermal resistance of all material layers or poorly ventilated air or lack of ventilated air in a building’s wall. 

Note that these are minimal requirements, definitely not optimal. As part of the Novoclimat program, the requirements will be stricter for all above-grade building parts.

Exterior Wall Insulation Standards

The recommended value for above-grade exterior walls is R-24.5.
Novoclimat’s recommended value for above-grade exterior walls is R-29.

The simplest way to improve the energy efficiency of exterior walls is by installing insulation panels on the warm side of the wall. Since the work is done inside, the insulation value is increased and the walls are rendered draft-proofed, without ever touching the exterior siding. Ideally, this should be done during the renovation stage, as requirements can be met without demolishing the space and maintaining most of the original square footage. 

Attic and Roof Insulation Standards

The recommended value for a roof is R-41.0
Novoclimat’s recommended value for a roof is R-51.0

In an attic, energy savings can be made by laying loose-fill insulation over the existing insulation materials. 

Foundation Insulation Standards

The recommended value for foundation walls is R-17.0
The recommended value for basement floors is R-5.0
The recommended value for basement slabs is R-7.5

To improve a basement’s energy efficiency, insulating from the inside is also simpler. Rigid panels will be installed up against the concrete walls or batt insulation will be inserted between the structure’s studs held against the foundation walls. 

A few exceptions or clarifications:

1. A foundation wall that cloisters a heated space from a non-heated space, from outdoor air, or adjacent ground must have an overall thermal resistance of R-17.0, no matter where the building is located.

2. A foundation wall with more than 50% surface exposure to outdoor air, as well as a part of a wood foundation wall, must have a total thermal resistance (RSIt) equal to that required for above-grade walls (R-24.5).

3. A wood foundation wall must be insulated just like an above-grade wall would be, no matter the surface area exposed to outdoor air. 

4. For composite foundation walls, the percentage of surface space exposed to outdoor air has to be calculated for all parts of a wall, and the RSIt value will apply solely to that specific part. 

What’s the best R-value to properly insulate a home?

Source: Canva

An R-value—or its metric equivalent: RSI value—is a material’s thermal resistance coefficient. The higher the R-value, the more effectively a specific material will be able to impede heat flow, which is what defines thermal resistance.

When referring to insulation, we often tend to forget that the total R-value accounts for the whole of the materials present in the building’s composition, rather than solely the ones considered in the “insulation” material category. Most building materials like wood, concrete, exterior siding and cladding, plaster, etc., have a significant impact on thermal performance, no matter how small it might be. 

When considering a house as a whole, it’s currently recommended to opt for an 80 Energuide rating with air barrier certification. Using the current building methods (concrete walls poured into an insulated form, spray polyurethane foam, etc.) makes reaching an 84 Energuide rating possible, 90 even, while also ensuring a permanent air barrier. 

What’s the R-value of insulation materials?

When it comes to insulation, the chosen material is key. While almost all insulation materials can be put to the test in new constructions—as long as it was planned ahead of time—with residential renovations, the four most commonly used insulation types are loose-fill, batt, rigid panels, and spray foam.  

Here’s a list of thermal resistance coefficients for various insulation materials:

Ensuring the Thermal Efficiency of a Building

Source: Canva

In Quebec, the thermal resistance standards to meet, when it comes to a new building or extending an existing structure, obviously differ. In most municipalities, these values add up to R-41 for roofs, R-24.5 for above-grade walls, and R-17 for foundation walls. 

Although we previously stated the recommended energy efficiency, a regular house will typically have an R-value ranging between 30 and 50. (For new homes, this number will increase to R-60.)

During a renovation process, reaching such targets is often very challenging—maybe even impossible. However, homeowners should still aim for these figures, especially if their heating expenses are rather high.

Quebec’s Insulation Standards: Ensuring Sustainable and Comfortable Buildings

Quebec’s insulation standards, as stipulated by the Construction Code, play a vital role in building sustainable, comfortable, energy-efficient structures. These ensure buildings that:

• Resist Quebec’s harsh weather conditions

• Minimize energy loss

• And provide pleasant indoor environments

These standards result from careful consideration with the goal of improving the quality of life for citizens while also contributing to limiting the carbon footprint. As such, by adhering to current standards, we’re not only fulfilling legal construction requirements but we’re also making a tangible step toward a future built on preserving the environment.