Where the line falls in Markham
If the work changes the structure of the house, or alters the plumbing, heating, cooling, or electrical systems, you generally need a permit. If the work is cosmetic and leaves those systems where they are, you generally do not. That single distinction resolves most of the question before you ever pick up the phone.
Three systems drive the answer. Structure. Plumbing and mechanical. Electrical. Structure, plumbing, and mechanical run through the City of Markham's building permit process. Electrical runs a separate path through the Electrical Safety Authority, which is a common surprise for homeowners who assume one permit covers everything.
Here is the cleanest test I can give you. A kitchen renovation that keeps every wall and every drain exactly where it is usually needs no building permit. Move one drain two metres and now it does.
Work that needs a permit
Work that touches the bones or the systems of the house. These are the projects we pull permits for as a matter of course:
- Removing or altering a load bearing wall, a beam, a post, or a header.
- Building an addition, a second storey, or a rear extension.
- Finishing a basement, because it involves framing, egress, insulation, and usually plumbing and mechanical work.
- Adding or relocating a bathroom, or moving plumbing fixtures to new locations.
- Cutting a new window or door opening, or making an existing opening larger.
- Building a secondary suite.
- Structural work to a deck above a certain height, or a deck attached to the house.
- Underpinning or lowering a basement floor.
- Changing the heating or cooling system layout, including new ductwork runs.
Gas work sits under its own licensing regime through the TSSA, and it belongs to a licensed gas fitter regardless of what other permits are open.
Work that usually does not
Finishes. Paint, wallpaper, flooring over an existing subfloor, new trim and baseboard, replacing kitchen cabinets in the same footprint with the same plumbing locations, and swapping a vanity or a toilet in place.
Replacing a window in an existing opening, same size, usually falls on the no permit side. Making that opening bigger does not. Re-shingling a roof is typically fine. Changing the roof structure is not.
I am giving you the principle, not a ruling. Markham applies the Ontario Building Code and its own zoning and property bylaws to your specific address, and the answer genuinely depends on the house. Heritage conservation districts add a review. Properties near a watercourse or in a regulated area can involve the conservation authority. Zoning controls how close you can build to a property line and how much of the lot you can cover, which is a separate question from whether the structure is sound.
Confirm your specific scope with the City of Markham's building department or with your designer before you commit. That call is free and it is faster than the alternative.
The permit is not the obstacle. The undocumented renovation you inherit from the previous owner is.
Removing a wall
If the wall carries load, yes, and you also need a designer or engineer to size the beam that replaces it. If the wall is purely a partition carrying nothing but drywall, generally no.
Do not decide this yourself from the direction the floor joists run. We have opened walls that looked like partitions and found a point load from a roof ridge landing on them, transferred down through two storeys by a previous renovation nobody documented. That is exactly the situation permits exist to prevent, and it is why we open a small inspection hole before anyone quotes a wall removal as a simple job.
What happens if you skip it
Three problems, and they arrive on their own schedule. The city can order the work exposed, corrected, or removed. Your insurer can question a claim connected to unpermitted work. And the buyer's lawyer will ask for permits at resale, which turns your finished basement into a discount.
The resale problem is the one homeowners underestimate. A finished basement with closed permits is a selling feature. A finished basement with no paperwork is a liability the buyer prices into their offer, or a condition that stalls the deal while everyone figures out what happens next. You paid for that basement either way. Only one version pays you back.
The insurance problem is quieter and worse. You will not discover the answer until you have a claim, and by then the work is behind drywall and the contractor is gone.
What the process asks of you
Drawings, a completed application, and a review by the city. For structural work the drawings have to be prepared by someone qualified, which means a designer with the right qualifications or an engineer depending on the scope. During construction, inspections happen at defined stages and the work has to be left open and visible for each one.
I will not quote you a fee or a timeline. Both change, both depend on scope, and you should get the current numbers from the City of Markham rather than from a blog post. What I will tell you is that the review takes real time and it belongs in your schedule from day one. Every homeowner who gets frustrated by permits is a homeowner who started thinking about them after they had already booked the demolition.
Who pulls it, and who holds it
We absorb the whole thing. Nathalia's drawings are prepared to permit standard from the start, we prepare and submit the application, we respond to city comments, we hold the permit, and we schedule the inspections so the trades are not standing around and the work is not covered up before an inspector sees it.
That last part matters more than it sounds. Coordinating inspections against a framing schedule is where projects lose weeks. When the same firm drew it, submitted it, and is building it, nobody is waiting on anyone else to send a file.
Send us your address and a plain description of what you want to do, including whether any wall is coming out and whether any plumbing is moving. We will tell you which side of the permit line your project lands on and what the drawings will need to show.