Most people ask what a renovation costs long before they ask what a designer costs. The second number is smaller, and it is usually the one that saves you from overspending on the first. Designer fees in Ontario are not a mystery once you know how they are charged — so here is a straight answer for 2026, and what the money actually buys.
The short answer
For residential work in the GTA, a designer usually charges one of four ways: by the hour, a flat design fee, a percentage of the project, or a flat fee based on square footage. As a rough guide for 2025–2026: hourly runs about $150 to $250 an hour; percentage-based fees are commonly 10 to 15 percent of the construction and furnishing budget (up to 20 percent on complex, full-service work); and per-square-foot design fees in the GTA generally land around $8 to $15 a square foot, more for high-end projects. A small one-room refresh and a full custom home are not the same job, and the fee will say so. Fees have drifted upward through 2025–2026 as material and trade costs have risen.
The four ways designers charge
- By the hour. Simple and transparent for smaller or open-ended work — a consultation, a finish plan, a few decisions you want a second set of eyes on. In the GTA, roughly $150–$250 an hour, with principal designers at the top of that range. You pay for the time you use.
- A flat design fee. A fixed price for a defined scope — a kitchen, a primary suite, a whole floor. Per room, GTA flat fees often run $1,500–$5,000; whole-project fees scale from there. You know the number up front, which makes budgeting easier.
- A percentage of the project. Used on larger renovations and new builds where the designer coordinates trades, drawings, procurement and schedule. Commonly 10–15% of the project budget, up to 20% on complex full-service work. The fee scales with the work because the management does too.
- A flat fee based on square footage. A flat design fee set from the home’s square footage — one number, agreed at the start. In the GTA this tends to land around $8–$15 a square foot depending on scope and finish level. It is the most predictable of the four: you know the full design cost before anything begins.
What moves the number
The fee follows the scope, not the square footage alone. It goes up with the number of rooms, the level of custom millwork and detailing, the set of drawings you need, and how much decorating and project management you want handled for you. Full furniture sourcing and procurement is usually charged on top — commonly a 20–30% sourcing fee on the furnishings. Design-only costs less than design plus full management and sourcing, because someone is doing less of the work for you.
What you actually get for it
A design fee buys a full set of documents your trades can build from — not just ideas on a mood board. A full-service package usually includes:
- Floor plans and furniture layouts
- Elevations
- 3D renderings of the key spaces
- Detail drawings for custom millwork and cabinetry
- Electrical and lighting plans, with reflected ceiling plans (RCPs)
- Finish and furniture specifications
Done well, the fee pays for itself. When the plan is right the first time, walls aren’t moved twice, the right finishes are ordered once, and trades aren’t left waiting on a decision — and that is where a renovation quietly saves or wastes money. The most expensive renovation is the one you have to redo.
How to keep it honest
Ask for the fee structure in writing before any work starts. Ask what is included — drawings, site visits, procurement, trade coordination — and what is billed separately. Ask how changes are handled. A clear scope and a clear fee protect both sides, and a designer worth hiring will give you both without being pushed.
How Studio Kimi works
Our base is a flat design fee set from your home’s square footage — one clear number, agreed before any work starts. Depending on the scope of work, we’ll tailor the approach to suit the project, but the aim is always the same: a straightforward, transparent fee, with no hourly meter running and no percentage that climbs as the budget grows. We work this way across Mississauga, Oakville, Burlington and the wider GTA.
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Frequently asked questions
How much does an interior designer cost in Ontario?
As a rough 2025 to 2026 guide in the GTA, hourly rates run about $150 to $250 an hour, per-square-foot design fees generally land around $8 to $15 a square foot, and per-room flat fees often run $1,500 to $5,000.
How do interior designers charge?
Designers typically charge one of four ways: by the hour, a flat fee per room or project, a percentage of the project cost, or per square foot. Which one fits depends on the scope and how defined the project is.
Recent Studio Kimi projects
A few recent Studio Kimi renovations across Oakville, Mississauga and the GTA:
- Mona — whole-home new build, Port Credit
- Duncan — design & build, Oakville
- Maple Grove — whole-home renovation, Oakville
- Erin Mills — kitchen & bathroom renovation, Mississauga
- Sandwell — interior design, Oakville
- Orleans — whole-home renovation, Mississauga