Unionville has always sold itself. The Main Street storefronts, the pond, the century homes tucked behind mature trees. But a few kilometres east, a piece of land that has sat quiet since 2023 is about to change the conversation.
As blogTO reported this month, the closed Toronto Buttonville Municipal Airport site is finally set to be redeveloped next year, after being mostly quiet since the facility shut down. For anyone who owns, or is thinking about buying, in Unionville or the pockets that border the old airport lands, that is not a footnote. It is the biggest shift to the area's shape in a generation.
The Unionville buyers already know
Unionville's appeal has never been complicated. Streets like Main Street Unionville, Carlton Road, and the enclaves around Toogood Pond attract buyers who want a walkable historic core with genuine architectural character: century brick homes, mature tree canopy, a Main Street you can actually stroll to for dinner. Move a little further out toward Village Parkway or the newer streets off Kennedy Road and you find larger executive homes on more generous lots, built in the last few decades, appealing to families who want space along with the Unionville school catchment and the GO Train access at Unionville station.
The buyers here tend to be families trading a Toronto condo or a smaller freehold for something with a real yard and a real sense of place, along with move-up buyers from elsewhere in Markham who have watched Unionville's Main Street retain its charm while so much around it has changed. I have walked this market with clients in both camps, and the pull is almost always the same: they want the small-town feel with the GTA commute still intact.
What Buttonville's redevelopment actually changes
The old airport lands sit close enough to Unionville's eastern edge that a large-scale redevelopment will not stay contained to its own footprint. New residential density, new retail, new road connections and transit investment tend to ripple outward, and that ripple can move in either direction for a buyer.
On one hand, a well-planned redevelopment can bring fresh amenities, improved infrastructure, and renewed interest to an area that has felt slightly overlooked next to Unionville's more storied core. On the other, density and construction activity change the daily experience of nearby streets in ways that matter to a family that chose the area precisely for its quiet.
This is the kind of shift I covered in more general terms in Where the $2-Million-Plus Homes Are: large parcels of underused land near established luxury pockets almost always get redeveloped eventually, and the neighbourhoods that absorb that change well tend to hold their premium, while the ones that fight it or get overwhelmed by it can see years of uncertainty in resale confidence.
What a buyer should look at closely right now
If you are considering a purchase in Unionville or the streets closer to the Buttonville lands, a few things deserve real attention before you write an offer, not after.
- Proximity and sightlines. Walk the property at different times of day. A street that feels tucked away today may end up backing onto a construction corridor or a new arterial road once phase one of the redevelopment breaks ground.
- Municipal planning documents. Markham's development applications and secondary plans for the Buttonville lands are public. Read them, or have your advisor pull the relevant sections, rather than relying on general news coverage.
- School catchment stability. Large new residential development can eventually shift enrollment pressure and catchment boundaries. If the school is part of why you are buying, ask how Markham's board has handled boundary changes near recent developments elsewhere in the region.
- Construction timeline versus your own horizon. If you plan to hold for a decade or more, a few years of nearby construction may be a worthwhile trade for the amenities that follow. If you are a shorter-term hold, the calculus is different.
- Resale positioning. Ask what a similar home sold for before major nearby development was announced elsewhere in Markham, and how the market read that news at the time. Precedent tells you more than speculation.
How the seller's side reads the same news
If you already own in the area, the Buttonville redevelopment is not a threat to manage quietly. It is a story to tell well.
Buyers researching Markham right now are seeing headlines about the airport site whether you mention it or not. A seller who can speak clearly and honestly about what the redevelopment means for their specific street, not in vague reassurance but with actual planning detail, comes across as credible in a way that matters in this market. That kind of preparation is part of what I wrote about in One in Four Over Asking: Markham's Mid-2026 Reality Check: the sellers who understand their own micro-market outperform the ones who rely on the neighbourhood's general reputation.
A property closer to the redevelopment site might position itself around future amenity and transit access. A property deeper in the historic core might lean into the insulation that distance provides. Neither story is better. The point is knowing which one is true for your address.
What this means for you
If you are buying in Unionville or nearby, do not let the Buttonville news scare you off or excite you into skipping due diligence. Treat it as a planning input, like a new school boundary or a road widening, something to understand street by street rather than neighbourhood by neighbourhood.
If you are selling, the redevelopment gives you a reason to have a sharper, more specific conversation with buyers about what is actually happening near your home, instead of leaving them to fill in the gaps with speculation.
Either way, the next twelve to eighteen months in this part of Markham will reward the people who did their homework early, quietly, and specifically to their own street.
What does the Buttonville redevelopment mean for the block you are on, or the one you are considering? Jai, with The Agency, Toronto, works with buyers, sellers, and custom-build clients across the GTA and is glad to have a ten-minute conversation about your own situation, offered as a courtesy, never a pitch.