Garden Suites and Secondary Suites: What Ontario's New Rules Mean for Homeowners

That backyard behind your house isn't just a backyard anymore, at least not legally. Ontario changed the rules around garden suites and secondary suites a few years ago, and the impact is still working its way through municipalities across Burlington, Oakville, Hamilton, and the surrounding area. Whether you're thinking about rental income, a place for aging parents, or simply want to understand how this affects your home's value, here's what's actually changed.

This is general information, not legal, tax, or construction advice. Zoning details vary by municipality, so always confirm specifics with your local planning department, a lawyer, and a licensed contractor before starting a project.

What Changed: Bill 23 and As-of-Right Zoning

Before 2022, adding a garden suite or extra unit to most Ontario properties meant applying for a zoning bylaw amendment. That process could take six to twelve months, cost thousands in planning fees, and still come back denied.

Ontario's More Homes Built Faster Act, known as Bill 23, changed that. It requires municipalities to allow up to three residential units as-of-right on most residential lots connected to municipal water and sewer services. In practice, that typically means:

• The main house
• An interior secondary suite, such as a basement apartment
• A detached accessory dwelling unit, commonly called a garden suite or laneway house

As-of-right means you don't need special approval to build one, as long as your project fits within the existing zoning envelope for your lot.

What "As-of-Right" Doesn't Cover

This is where a lot of homeowners get tripped up. As-of-right zoning covers the use, meaning you're allowed to build a second or third unit at all, but it doesn't override every local rule. Setbacks, height limits, lot coverage, parking requirements, and tree protection bylaws still apply, and they vary from one municipality to the next.

If your project doesn't fit within these envelopes, you can apply for a minor variance through your local Committee of Adjustment, but expect that to add three to six months and several thousand dollars in fees.

Financing a Secondary Suite

Building a legal secondary suite is a real investment, and there are a few ways homeowners are funding it.

Rental Income Potential

A well-built basement apartment or garden suite can generate meaningful rental income, generally somewhere between $1,500 and $2,800 per month across the GTA, depending on size, finishes, and location. That kind of income can significantly offset a mortgage, which is part of why demand for these projects has grown so quickly.

A Tax Detail Worth Knowing

If you build a secondary suite and rent it out, you may be treated as a builder for HST purposes, which can trigger what's called a self-supply charge under the Excise Tax Act. Many homeowners can offset this through the New Residential Rental Property Rebate, but it's a detail that catches people off guard. This is exactly the kind of thing worth reviewing with an accountant before you start construction, not after.

What This Means If You're Buying or Selling

For sellers, a legal, permitted secondary suite can be a genuine value driver, especially with rental income now a real consideration for buyers weighing affordability. The key word is legal. An unpermitted basement apartment can create complications during a sale, from financing issues for the buyer to insurance questions, so it's worth confirming your suite's compliance before listing. Our Sellers Guide covers what to prepare before your home goes to market.

For buyers, a property with an existing or potential secondary suite can be a smart way to offset your own mortgage from day one. If you're evaluating a home with this in mind, our Buyers Guide walks through what to look for and what to ask.

Curious What This Means for Your Property?

Whether you're weighing adding a suite to increase rental income, or wondering how one affects what your home is worth today, we're happy to talk through the specifics for your property, wherever you are across Burlington, Oakville, Hamilton, and the surrounding communities. Our free home evaluation gives you a real, current number to start from. Contact us any time, or book a call directly with our team.