What is the average cost to drywall a detached garage in Brampton and convert it to a finished workspace?

Converting a detached garage in Brampton to a finished workspace typically costs $8,000 to $18,000 for the full drywall scope — including insulation, vapour barrier, fire-rated drywall, taping, finishing, and primer — depending on the garage size, ceiling height, and the finish level you choose. A standard two-car detached garage (roughly 20x22 feet or 440 square feet of floor space) falls in the middle of this range at approximately $10,000 to $14,000.

Before any drywall work begins, you need to understand the Ontario Building Code requirements and permit implications. Converting a detached garage to a habitable workspace requires a building permit from the City of Brampton. The permit process ensures the space meets code for insulation, ventilation, electrical, heating, and fire separation. This is not optional — unpermitted garage conversions can result in fines, orders to restore the garage to its original condition, and complications when selling your home. Permit fees in Brampton typically run $300 to $800 depending on the scope of work.

Insulation is the first major cost component. Brampton is in Ontario's Climate Zone 6, and the Ontario Building Code requires minimum R-20 insulation for walls in a garage conversion (R-24 for above-grade walls in new construction or significant renovations). For a detached garage that was originally uninsulated, framing the walls with 2x6 studs at 16 inches on centre and filling with R-22 batt insulation is the most common approach. The ceiling requires R-32 to R-50 depending on whether the space above is conditioned. Insulation and framing for a two-car garage typically costs $3,000 to $6,000 including materials and labour. A 6-mil polyethylene vapour barrier must be installed on the warm side of the insulation before any drywall goes up — this is code-required in Ontario and critical for preventing condensation and mould inside the wall cavity.

The drywall itself must meet fire-rating requirements. Under the Ontario Building Code, the wall between an attached garage and the house requires 5/8-inch Type X fire-rated drywall with a 45-minute fire resistance rating. For a detached garage being converted to a workspace, the fire separation requirements depend on the building's proximity to the property line and whether the garage shares any structure with the house. Your building inspector will specify the exact requirements during the permit process. At minimum, most Brampton contractors install 5/8-inch Type X drywall ($20 to $28 per 4x8 sheet) throughout a garage conversion for added fire safety and superior rigidity. For the ceiling, 5/8-inch board is standard to prevent sagging.

The drywall hanging and finishing costs for a typical two-car garage break down as follows. Walls in a 20x22-foot garage with 8-foot ceilings represent approximately 670 square feet of wall surface (after deducting for the garage door opening, service door, and windows). The ceiling adds another 440 square feet. Total drywall surface: roughly 1,100 square feet. Hanging costs $2.50 to $4.00 per square foot for walls and $3.50 to $5.50 for the ceiling. Taping and finishing to a Level 4 standard adds $2.00 to $3.50 per square foot. Materials (drywall sheets, compound, tape, corner bead, screws) run approximately $1,500 to $2,500 for a two-car garage.

For a workspace rather than a living space, you have some flexibility on finish level. A Level 4 finish is standard for paint-ready walls and is suitable for most workshop and office conversions. If you are creating a professional studio, home office with video conferencing, or any space where appearance matters, Level 4 is the right choice. For a workshop where aesthetics are secondary to function, a Level 3 finish ($1.50 to $2.50 per square foot) — where joints are taped and coated but not sanded to a perfectly smooth surface — saves money and is perfectly adequate if you plan to apply a texture or are not concerned about a flawless paint finish.

Additional costs to budget for include electrical work (most detached garages need upgraded wiring for workspace use — $2,000 to $5,000), heating (a ductless mini-split is the most common solution for detached garages at $3,500 to $6,000 installed), and flooring ($1,500 to $4,000 for epoxy or laminate over the concrete slab). These are outside the drywall scope but essential for a functional workspace.

A garage conversion is not a DIY drywall project — the permit requirements, fire-rated assemblies, vapour barrier installation, and ceiling work all demand professional expertise. Browse drywall professionals in the Brampton area through the Toronto Construction Network directory at torontoconstructionnetwork.com/directory?trade=insulation.