insulating a basement

A guide to energy-efficient basement upgrades

Maximize your energy savings while increasing your living space with these tips.

Canadians spend billions on home improvements each year, including basement upgrades. And with many of us spending more time at home, maximizing our spaces for work and play is at the top of many summer to-do lists.

If you’re planning to upgrade your basement, here’s what to keep in mind to get the most out of your space, while still saving energy.

Prioritize insulation

Regardless of how you plan to use a finished basement, you’ll want it to stay warm and dry. Basements can account for about 20 per cent of a home’s heat loss, according to Natural Resources Canada. Using quality insulation can make all the difference to the comfort of your basement.

Before you upgrade or add insulation, you may want to consult with a professional about additional measures you might need to take, including waterproofing or radon remediation, especially for older homes.

Once you’re ready, you’ll need to choose an insulation type for your walls. There are several, including batt and blanket insulation, loose-fill or blown-in insulation, rigid foam board and spray foam.


Here’s a breakdown of what each looks like:

Blanket insulation

Batt and blanket insulation

Batt and blanket insulation are the most commonly used types of insulation for unfinished walls, floors and ceilings, and the easiest to install. Made of flexible fibres like fibreglass, rock wool or natural fibres, this type of insulation can be cut to fit the space you are filling.

Loose insulation

Blown-in or loose-fill insulation

Blown-in or loose-fill insulation is best suited for attics, or other hard-to-reach areas like sloped ceilings or roofs. It is also used for filling cavities or topping up existing insulation. Made from fibreglass or cellulose, this type of insulation can be poured or blown into cavities. Keep in mind, though, that blown-in and blanket insulation are not a substitute for air sealing.

Board insulation

Rigid board insulation

Made from mineral fibre or foam plastics, rigid board insulation is typically a rigid board used to insulate walls, roofs and foundations. More expensive than blanket or loose-fill insulation, the foam material has a higher insulating value for a given thickness and is more water resistant than fibreglass insulation.

Foam insulation

Spray foam insulation

Spray foam insulation is an expanding foam that is sprayed into the surface or cavity in which it is being installed. This type of insulation is best suited for attic and wall insulation or other cavities that need tight air sealing.


You can also use a combination of these types based on your budget and the foundation of your home. For example, rigid foam board insulation works well for evenly vertical walls, such as poured concrete or concrete block, but it may not work as well in older homes with uneven basement walls. Closed cell polyurethane spray foam, meanwhile, is high quality, works well for uneven walls and may help control dampness. However, it should only be applied by a certified installer, especially to ensure you have correct fire protection.

The cost of materials and labour and the use of the space will all influence your decision. Generally, when selecting insulation, you should consider R-value. It shows how effective an insulation is at limiting heat transfer, or the flow of heat into and out of your home. The higher the R-value, the better the resistance to heat loss, which leads to potential savings on heating and cooling costs year-round.

You can also insulate your walls from the outside, which can help deal with water leakage, this a much more intensive process that requires excavation. Natural Resources Canada provides an in-depth, step-by-step guide on interior and exterior basement insulation.

When insulating, be sure to also seal air leaks around the sill plate where the wood structure meets the concrete foundation, and in spots where pipes and vents go through the walls and foundation.

Along with preventing air leaks around walls, you may want to avoid heat loss through the floor. While this kind of heat transfer doesn’t contribute much to overall energy inefficiency, using insulated subflooring material will likely keep your space more comfortable, especially during the colder months.

Finally, undertaking a basement upgrade is also a convenient time to maintain any exposed ductwork before it’s sealed behind finished walls or ceilings. Use sealing measures around any leaky ductwork to keep heating and cooling more efficient.

Upgrade windows and doors

As you upgrade or add insulation to reduce heat transfer, you may also want to consider replacing windows and exterior doors with more energy-efficient models. Even if they’re not ageing, sometimes newer homes may have window models that are not as efficient as they could be. ENERGY STAR®-certified windows are 20 per cent more energy efficient than standard windows, while doors with this certification are 15 per cent more efficient than ones without.

Just as insulating walls can keep your basement more energy efficient, sealing air leaks around existing windows can also help, even if you aren’t replacing them. Weatherstripping and exterior caulking around doors and windows can both provide a tighter air seal for your home. 

Keep in mind that installing windows in your basement is often more complex than installing windows elsewhere in your home. Get multiple quotes from different qualified professionals before your installation. A professional can also help ensure your windows are up to building code regulations, especially if you have bedrooms in the basement or plan to create a rental unit.

Get smart about lighting and temperature

Basement lighting is often an afterthought, but upgrading it can improve the overall look and comfort of the space, and can save energy, even in semi-finished areas. Upgrade older fluorescent or halogen lighting to LED lighting throughout the basement to reduce electricity costs.

When planning your basement lighting, consider installing separate switches and dimmers to light up specific areas, rather than lighting the entire basement. For example, you may have a space that doesn’t need overhead lighting if you’re only going to be using one corner of the basement for an office space or play area.

While you’re upgrading electric outlets and lighting, consider using smart switches or smart plugs for more control over your lighting and other electronics.

Smart plugs plug into your standard wall outlets and can be configured using an app, allowing you to control any device, light or appliance that is plugged into it, like a lamp fixture, fan or gaming console. Some smart plugs have features such as monitoring energy consumption and providing reports that can help you optimize its use to save money.

Smart switches, meanwhile, replace existing traditional switches. You’ll still be able to turn lights on and off from a wall switch, but they have added benefits like dimming and remote-control capability through a dedicated app connected to Wi-Fi or data if you’re away from your home.

Ensuring all electrical work is done safely and up to building code regulations is important, so consult with a professional as needed. 

You can also take advantage of other smart technology, such as sensors that connect to a smart thermostat to help maintain a comfortable temperature.

Rethink your appliances

Basements are often home to major appliances. If you’re planning to upgrade the appliances in a basement laundry area, remember to look for ENERGY STAR® certified clothes washers and dryers. Consider leaving space for a clothes drying rack as well, which can help you save energy all year. 

If you have an additional living space, such as a kitchen in the basement, consider upgrading appliances there as well. Remove old appliances you’re no longer using, such as freezers or additional refrigerators – which are often energy hogs – or upgrade to more energy-efficient models. 

Depending on the age and quality of your HVAC system, this may also be a good time to upgrade heating and cooling equipment, such as your furnace if it’s nearing the end of its life. You may want to consider installing an ENERGY STAR® certified dehumidifier as well.

Whatever your plans are for your basement, prioritizing energy-efficient upgrades will help you get more out of your home, all year long.

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