Repairing a broken pane or weather-stripping on a Unionville heritage home needs no heritage permit, but replacing a window or door does. It's a free minor permit from the City of Markham, so apply before ordering anything.
Windows and doors are the part of an old house people most want to "just swap", and the part Unionville's heritage rules care about most. Markham's own heritage page says it's important to retain original or early building fabric such as windows, wall claddings and architectural elements. This guide covers the window and door side of that rule: what you can fix freely, what needs a permit, and how your home's heritage status changes the answer. For other exterior jobs, see our guide to exterior repairs in Unionville's heritage district.
First, find out which kind of heritage home you have
"Heritage home" covers three different situations in Markham, and the rules differ:
- Inside the Unionville Heritage Conservation District. Markham protects Unionville under Part V of the Ontario Heritage Act. Its permit page says a heritage permit is required for external alterations to any property in a district, both heritage and non-heritage buildings. A newer house on a heritage street is covered too.
- Individually designated. A property designated under Part IV of the Act. Markham says over 350 properties are individually designated, and you can check yours on the City's Register of Property of Cultural Heritage Value or Interest. Under the Act, an owner of a designated property can't make alterations likely to affect its heritage attributes without the council's consent.
- Listed only. The municipal register can also include properties that council believes have cultural heritage value but that haven't been designated. Markham's permit page ties heritage permits to individual designation or a district, and doesn't name listing as a trigger. What listing does change is demolition: the Act requires the owner to give council at least 60 days' written notice before demolishing or removing a building or structure on a listed property.
Listing isn't permanent either. For properties listed as of December 31, 2022, the Act says council must remove them from the register unless it gives a notice of intention to designate by January 1, 2027, or a later date set by regulation. If you're unsure, check the register rather than relying on what a neighbour or a past listing told you.
What you can do without a heritage permit
Markham's permit page lists these as not needing a heritage permit: general repairs to weather-stripping, eaves troughs, roofs, chimneys, fences and existing cladding, and repair of broken window panes to original specifications. The phrase to hold onto is "to original specifications". Re-glazing a cracked pane with glass that matches the old one is a repair. Swapping a divided-light sash for a single sheet of glass changes how the house looks.
What needs a minor heritage permit
The same page lists "removal and replacement of windows or doors" among its examples of Minor Heritage Permit projects. It also lists exterior repairs that change the appearance of the building, painting, and changes to architectural decorations such as trim. So a repair that alters the look of a window or door can still land in this category. Markham says there is no fee for a minor permit, and staff approve applications that comply with the district plan's policies and guidelines.
The City says Council alone has the final power to deny an application. Applications that don't comply with policy go through the Heritage Markham Committee, so a replacement that departs from the plan can take noticeably longer than one that fits it.
Repair first, replace last
Markham's heritage districts page states the principle plainly: it is better to maintain than to repair, better to repair than to restore, and better to restore than to replace. In practice, an old sash with a rotted sill or sticking cords is usually a repair conversation before it's a replacement one, and the repair is also the route with the least paperwork. A craftsman who goes straight to "we'll rip them all out" hasn't followed the City's own order of preference. Ask what repair would involve before you accept a replacement quote.
The district plan is where the specifics sit, such as what materials and styles suit a given building. Markham's web pages describe the plan but don't spell out window rules, so read the Unionville plan or ask Heritage Section staff before you order custom windows or doors.
Old paint: don't sand it
Sashes rub, doors drag and paint gets scraped when you re-glaze, which is exactly how old paint becomes dust. Health Canada says a home probably contains lead-based paint if it was built before 1960, and the exterior may contain it if built between 1960 and 1990. It advises against using sanders, heat guns or blowlamps to remove it, because they create lead dust and fumes, and suggests a chemical paint stripper paste instead. Ask any contractor how they'll handle paint before they start on an older frame.
How to apply
- Check your status on the Register of Property of Cultural Heritage Value or Interest and the Unionville district map on Markham's heritage permit page.
- Talk to Heritage Section staff first. The City says consultation on whether you need a permit is highly recommended.
- Apply through ePLAN, Markham's online portal. Registering is free. For a minor permit with no checklist, you upload drawings, plans, photographs or specifications that help the review.
- Check whether you also need a building permit. A heritage permit is separate; see how building permits work in York Region.
- Hold the order. Don't place a custom window or door order until the permit answer is in writing.
Quick answers
Do I need a permit to repair a window on a heritage home in Unionville?
Not for a broken pane or weather-stripping. Markham's permit page says repair of broken window panes to original specifications and general weather-stripping repairs need no heritage permit, though replacing a window or door does.
Can I replace the windows on a Unionville heritage home?
Only after applying. Markham lists removal and replacement of windows or doors as a Minor Heritage Permit project for designated properties and anything in a heritage district, and the application is free.
What is the difference between a listed and a designated heritage home in Markham?
A designated home is protected under the Ontario Heritage Act, while a listed one is only on the municipal register. Markham's permit page ties heritage permits to designation or a heritage district, not listing.
Is old window paint dangerous to scrape or sand?
It can be. Health Canada says a home built before 1960 probably contains lead-based paint, and it advises against sanders, heat guns and blowlamps because they create lead dust and fumes.
Where do I apply for a heritage permit in Markham?
Through the City's online ePLAN portal. Registering is free, and for a minor permit without a checklist you upload photos, drawings or specifications of the work.
A short check before you call anyone
Most of the risk here comes from guessing: assuming a repair is exempt when it changes the look, or ordering windows before the permit is settled. Knowing your status, the exempt list and the free minor permit route takes a short phone call or an online check and usually saves a redo.
Related reading
- More home repair guides for Markham
- Exterior Repairs on a Main Street Unionville Heritage Home: What Needs Sign-Off
- Window and Door Repair on a Heritage Home in Downtown Aurora: Repair vs. Replacement
- How Do I Know If a Contractor Is Licensed in Ontario?
If you'd like a price for a repair or replacement on an older home, you can ask for a fixed price from Rhodex.
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