A buyer walking Main Street Unionville sees the price of the house. Another consideration is the price of everything they might want to do to it afterward.
Unionville has heritage charm, cobblestone-adjacent streets, and a Main Street full of boutiques and cafes near Toogood Pond. Heritage designation in Unionville isn't just a label on a plaque outside a few landmark buildings. It brings municipal review for exterior changes and other projects within the district boundary, and it can change how long a renovation takes, what it costs, and in some cases what you're allowed to do at all.
The Permit Question to Ask Before Closing
Markham has designated Thornhill, Markham Village, and Unionville as heritage conservation districts under the Ontario Heritage Act. A fourth area, Buttonville, remains a study area rather than a full designation. Unionville's district is one of the oldest and best known of its kind in Ontario, which is part of why the neighborhood photographs so well and why buyers gravitate toward it in the first place.
The detail that catches people off guard is this: designation doesn't apply only to the obviously historic buildings. Once a property sits inside the district boundary, every owner, not just owners of individually designated landmarks, needs city approval before making exterior changes. A 1980s infill home on a heritage-district street faces the same review as a Victorian farmhouse. The house doesn't need to look old to be governed by the rules that protect the old ones.
Minor Permit, Major Permit, and the Line Between Them
Markham splits heritage approvals into two tracks under the city's heritage permit by-law, and which track your project falls into determines whether you're waiting a week or waiting a season.
A Minor Heritage Permit covers routine, lower-impact work. This is the track for:
- Exterior painting, new siding, or roofing
- Driveway replacement or changes
- Fencing, hard landscaping, and exterior lighting
- Repairs to weather-stripping, eaves troughs, chimneys, and existing cladding
A Major Heritage Permit is where the timeline stretches. Heritage staff evaluate the proposal against the district's heritage character, and Toronto Construction Network reports that this review can add two to four months on top of the standard building permit process. If you're planning a kitchen addition that pushes into a heritage-visible wall, or replacing windows in a way that changes their original proportions, budget for that extra season before you budget for the contractor.
The Line Runs Through the Walls, Not Just the Facade
Here's the part that surprises even buyers who did their homework on the facade rules. Interior renovations are generally less restricted, but that's not the same as unrestricted. If a structural change affects the building's heritage attributes, it can still require review, even if nobody walking down the street would ever see it.
That single clause is the reason a heritage-district purchase deserves a different due-diligence conversation than a standard resale. It's not enough to ask "can I change the windows." The better question, before you write an offer, is "what has the city already flagged as a heritage attribute on this specific property, inside and out." Heritage Markham staff can answer questions about a specific property before you close.
A Main Street Example: 31 Victoria Avenue
A property currently listed on Victoria Avenue makes this concrete. The home dates to roughly 1875 and sits on a 66 by 132 foot lot backing onto a ravine and river, listed in July 2026 at $3,880,000. The listing describes original pine floors, two staircases, a wraparound verandah, and three fireplaces, all preserved rather than replicated. The listing also notes the home is known locally as a filming location for the original Gilmore Girls production, a detail worth mentioning as a piece of local color rather than a verified production credit.
What makes the property genuinely instructive isn't the film trivia. It's the second building on the lot: a detached structure, formerly the village bakery from 1910 to 1984, since restored and fully serviced with heat, air conditioning, electricity, and internet. But because that outbuilding sits inside the same heritage conservation district as the main house, any future exterior change to it runs through the identical Heritage Permit process. Two structures, two centuries apart in original use, governed by the same review.
This is the version of Unionville's heritage market that a median price can't show you. The number on the listing tells you what you're paying to acquire the property. It says nothing about what you'll be permitted to change, or how long the city will take to decide.
What the City Offers to Offset the Friction
The city runs a Heritage Property Tax Reduction Program and a Heritage Loan Program, along with a Commercial Façade Improvement Grant and a Commercial Signage Replacement Grant.
Buyers can learn about the programs by contacting the city's heritage planning staff directly, which is exactly what Markham's own guidance recommends before you design a project, not after you've already committed to one.
What This Means If You're Comparing Homes
If you're weighing a heritage-designated Main Street property against a comparable home elsewhere in Markham that sits outside a conservation district, the sale price is only half the comparison. The other half is the renovation timeline and the approval risk. A buyer who prioritizes flexibility over the next decade is buying a very different asset than a buyer who values the district's heritage character.
Neither answer is wrong. But they're different answers, and the heritage designation is the variable that decides which one applies to you. Before an offer goes in on anything inside Unionville's district boundary, a conversation with Heritage Markham staff about what's already flagged on that specific property is worth more than another walkthrough.
FAQ
Does heritage designation apply to every home in the district, or just the historic-looking ones? Every property within the boundary of a designated heritage conservation district requires approval for exterior alterations, new construction, or demolition, regardless of the building's age or architectural style.
How long does a Major Heritage Permit typically take? Heritage committee review for Major Heritage Permits can add two to four months to a project timeline, on top of standard building permit processing.
What work do Minor Heritage Permits cover? Minor Heritage Permits cover routine items like painting, roofing, driveway changes, and fencing, and move faster than Major Permit applications.
Can interior work ever require heritage review? It can. Interior renovations face fewer restrictions overall, but structural changes that affect a building's heritage attributes may still require review even when the work isn't visible from the street.
Can the city refuse to allow a heritage property to be demolished? Markham's heritage-protection guidance says Council can deny a demolition request affecting a designated property, and can delay a demolition request on a non-designated or listed property while its heritage significance is evaluated.
If you're weighing a purchase inside Unionville's heritage district, or you own a designated property and want to understand what a future sale or renovation actually involves, Bryan Lim can walk through the specifics with you before you're locked into a timeline you didn't plan for. Let's Connect.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
