How to Add a Legal Garden Suite in the GTA (And Actually Make Money From It)

Your backyard is sitting there right now. Empty. Underused. While your mortgage is bigger than ever and the GTA rental market is tighter than it’s been in decades.

Here’s the thing most homeowners don’t know: Ontario law changed. Since 2022, you can legally add a garden suite — a fully detached rental unit in your backyard — on most residential properties across the GTA. No rezoning drama. No lengthy variance process. Just a building permit and the right team.

That backyard? It could be paying you $2,200 a month.

What Exactly Is a Garden Suite?

A garden suite (also called a backyard suite or detached ARU) is a self-contained residential unit built on your property — separate from your main home. It has its own entrance, kitchen, bathroom, and living space. It’s legal. It’s permanent. And under Ontario’s More Homes Built Faster Act, it’s now permitted as-of-right in most municipalities.

We’re talking Toronto, Mississauga, Brampton, Vaughan, Oakville, Richmond Hill — all of them. Your city, your backyard, your new income stream.

Why GTA Homeowners Are Building Garden Suites Right Now

GTA rents aren’t going down. The average one-bedroom in the 905 region still commands $2,000 to $2,400 per month. A well-built garden suite can offset your entire mortgage payment — or close to it.

Typical Garden Suite Income Scenarios

Scenario A: A Brampton homeowner builds a 600 sq ft garden suite for $195,000. They rent it for $2,100/month. After mortgage financing, they’re cash-flow positive within 8 years — and the property value went up $140,000.

Scenario B: A Richmond Hill family builds a 750 sq ft suite for aging parents. No rent. But the family saves $3,800/month they were spending on assisted living. ROI in under 5 years.

The Permit Process — Less Scary Than You Think

A garden suite permit in Toronto or the GTA typically takes 4–6 months from application to approval when your drawings are done right. The Ontario Building Code has clear requirements — setbacks, lot coverage, height, servicing — and a team that knows them can get your permit through without surprises.

Your lot must meet minimum size requirements. The suite must respect rear and side yard setbacks (usually 1.5m to 3m). It must connect to existing services — water, sewer, electrical. And the structure must comply with the Ontario Building Code for energy efficiency, fire separation, and accessibility.

What Does a Garden Suite Actually Cost in 2026?

Expect to invest between $180,000 and $280,000 for a turnkey garden suite in the GTA, depending on size, finishes, and site conditions. That includes design, permits, construction, and connections.

How ARU Makes the Process Turnkey

At ARU, we handle the entire process — from feasibility check and architectural drawings, through permit application and construction, to your final walk-through. One team. One contract. No subcontractor juggling.