Do You Need a Building Permit to Finish Your Basement in Ontario?

John Barnhart
Jul 25
2 min read

Updated: Sep 5

Thinking about finishing your basement?

Finished basement in Ontario with kitchenette and kids’ play area — renovation likely required a building permit — This finished basement includes structural changes and plumbing — the kind of renovation that typically needs a permit in Ontario.

It’s one of the best ways to increase living space and boost your home’s value — but many homeowners don’t realize they need a permit to do it legally. In Ontario, skipping this step can mean failed inspections, costly delays, and even being forced to undo your renovations.

Here’s what you need to know before you start swinging a hammer.

✅ When Do You Need a Permit?

You need a building permit if your project includes any of the following:

🧱 Building or removing walls
🚿 Adding a bathroom, laundry, or kitchenette
🛏️ Creating a bedroom or basement apartment
🔧 Installing or changing plumbing, electrical, or HVAC
🪟 Cutting new windows or doors
🔥 Installing a fireplace or woodstove
⛏️ Lowering the basement floor

If you're doing cosmetic updates like painting or flooring, you don’t need a permit — but the moment you touch structure or systems, you’re into permit territory.

📄 What Do You Need to Get a Basement Permit?

To apply for a permit, most municipalities in Ontario require:

Code-compliant permit drawings (done by a BCIN designer or engineer)
Floor plans showing all layout changes
Details of any plumbing, HVAC, or structural work
Fire safety details (egress windows, smoke detectors, fire separation)

We can handle all of this for you.

⏱️ How Long Does a Permit Take?

Most cities aim to review residential basement permits in 10 business days, depending on how busy they are and how complete your application is.

Want to avoid delays? Start with clear, accurate drawings. That’s where we come in.

⚠️ Risks of Skipping the Permit

You could be forced to remove finished work
Your insurance may not cover unpermitted renovations
You could face fines or legal issues
It could block or delay a home sale

👷‍♂️ How We Help with Basement Permit Drawings in Ontario

At The Building Permit Guy, we create fast, affordable, and code-compliant permit drawings for basement renovations across Ontario. With years of inspection and design experience, we know exactly what your municipality expects — and we deliver plans that get approved. If you’re creating a separate basement apartment (ADU), see our ADU services. For general basement renovations, visit our Basement Renovation Permit page.