7 Essential Tips for Enhancing Your Garage's Energy Efficiency

Your garage is likely one of the least energy-efficient spaces in your home, but it doesn’t have to stay that way!

Many homeowners overlook their garage as an extension of their living space, seeing it as more of an outdoor area. However, attached garages should really be considered just like any other room in the house. The more energy-efficient your garage is, the smaller your home's carbon footprint will be. Inefficient garages tend to draw in frigid air during winter and scorching air in summer, which then seeps through the walls and ceilings into the living areas, causing major disruptions to the overall energy efficiency of your home. But there's no need for it to be this way. Here’s how you can improve it.

7: Add Insulation to the Garage Walls

Cost: Starting at $1,000 for a standard two-door garage.

Many older homes (and even some newer ones) were built without insulation in their garage walls. These homes often only feature exterior siding, radiant sheathing, and a layer of particle board protecting the walls from the weather. Insulating the walls of your garage is typically as simple as placing the proper R-value insulation between the joists, or having it blown in through small openings in the drywall of the garage’s sides and ceiling.

6: Seal the Gap Between the Walls and Concrete Floor with Caulk

Cost: $5 for a few tubes of caulk.

Many garages are built without the proper compressible foam between the lower framing and the concrete floor. Over time, this connection can swell, shrink, and shift, creating gaps that allow outside air to seep in. You can use a foam sealant or a latex/silicone-based caulk to seal this commonly neglected area.

5: Seal the Door Between the House and Garage

Cost: $10 and up for weatherstripping.

Start by ensuring that weatherstripping is properly installed around the entire door frame and is intact, flexible, and effective in sealing out most of the garage's air. You can use smoke to detect leaks around the door, or a simpler method is to turn on the garage lights, then switch them off from the inside of the door and check for any light leakage. Next, verify that your threshold is sealing the bottom of the door properly. If replacing the entire threshold is too much trouble, you can use a simple draft stopper. Another often overlooked task is to caulk the trim around the door, both inside and out. Air can enter through the inner construction of the door frame if the decorative trim isn't sealed correctly.

4: Add Insulation to the Garage Door

Cost: Ranges from $50 to over $1,000.

Even if your garage walls are well-insulated, many builders skip the expense of installing an insulated garage door. This undermines the effectiveness of the wall insulation, as a thin sheet of aluminum is highly effective at transferring both heat and cold from the outside directly into the interior. You can opt for a new insulated door for a few hundred dollars, or save money by purchasing an insulation kit. These kits feature thin sheets of double-bubble radiant insulation that can be applied to the inside of the garage door to reflect heat away in the summer and retain warmth during winter. Alternatively, you can use foam board insulation for the same effect.

3: Insulate the Electrical Outlets and Light Switches in the Garage

Cost: $5 for specialty foam gaskets for outlets and switches.

It's crucial to seal every tiny gap in your garage to prevent air from leaking into your living spaces. Besides the hot or cold air from the garage, you should also be concerned about carbon monoxide that can enter after a vehicle leaves or enters the garage. These fumes can slip through the smallest cracks in the walls and make their way into your home without you even realizing it.

2: Utilize Passive Solar Heating

Cost: Starting at $50 for a DIY setup.

One of the best wintertime luxuries for a workshop is having a heated garage. However, using gas or electric heaters for this can be both pricey and environmentally costly. On the other hand, if you can capture the sun's heat, you can stay warm without feeling guilty about energy use. Building a passive solar heater is relatively simple, requiring only basic hand tools and some crafting skills.

1: Seal the Cracks in Your Garage’s Concrete Floor

Cost: $5 for a tube of concrete sealant.

While poured cement isn’t the ideal form of insulation, its effectiveness significantly worsens when the surface develops cracks. Even the smallest crack allows cold air and ground gases to infiltrate the garage. Additionally, if you frequently introduce water into these cracks, like after driving through a snowstorm, the water can freeze, expand, and cause the concrete beneath to shift. If the slab shifts too much, the floor becomes uneven, which may prevent the garage door from properly sealing when closed.