Can insulation be added without removing drywall?

Yes, insulation can often be added to existing walls without removing drywall using blown-in or injection foam methods, though the effectiveness depends on your home's construction and current insulation situation.

The most common approach for Toronto homes is blown-in cellulose or fiberglass insulation. Contractors drill small holes (about 2.5 inches) into each wall cavity from either the interior or exterior, then use specialized equipment to blow loose insulation into the empty spaces. The holes are then patched and painted, leaving minimal visible damage. This method works particularly well in older Toronto homes built before modern insulation standards, including many century homes in neighborhoods like Cabbagetown, The Beaches, and Riverdale.

Injection foam insulation is another option where expanding foam is injected through similar holes. This creates a more complete air seal but costs significantly more - typically $3-6 per square foot versus $1.50-3.50 for blown-in cellulose. The foam method works especially well for homes with irregular wall cavities or significant air leakage issues common in Toronto's older housing stock.

Toronto-specific considerations include working around the city's heritage home requirements if you live in a designated area, and timing the work during warmer months when exterior access is easier. Many GTA contractors prefer exterior drilling to avoid interior patching, though this isn't always possible with brick veneer construction typical in Toronto neighborhoods.

Professional assessment is crucial before proceeding. A qualified insulation contractor needs to determine if your wall cavities are empty, partially filled, or contain old materials like vermiculite (which may contain asbestos in pre-1980 homes). They'll also check for electrical wiring, plumbing, or HVAC components that could complicate the installation.

When this method won't work: Homes with existing batt insulation, significant moisture issues, or certain wall constructions may require drywall removal for proper insulation upgrade. Steel-framed homes or those with complex interior layouts may also need alternative approaches.

Next steps: Get quotes from at least three insulation contractors in the Toronto Construction Network directory. Expect to pay $2,500-6,000 for a typical Toronto home, with the work taking 1-2 days. Many contractors offer free energy assessments and can help you access available rebates through programs like Canada Greener Homes.