Window repair Markham
In Markham's four heritage districts a pane repaired to original specs needs no heritage permit. Fogged units swapped in the frame you already have.
What to do while you wait.
Keep children, pets, and anyone without proper footwear away from the broken glass. Shards can scatter several feet from the break point.
Glass still attached to the frame can fall without warning and cause deep cuts. Leave loose pieces alone until our technician arrives.
If you must walk near the area, wear closed-toe shoes and work gloves. Thin slippers or bare feet are a serious hazard.
Use a heavy tarp, thick cardboard, or plastic sheeting secured with tape to block wind, rain, and debris until we arrive.
Take photos of the damage from both inside and outside. These help our technician prepare the right glass size and type before arriving.
Call 647-803-2730. Our emergency line is staffed 24/7 including nights, weekends, and holidays.
Overview
Markham has two kinds of window stock side by side. Most homes are suburban houses and townhouses built since the 1970s, when the new town's population took off from about 56,000 in 1976 to 338,503 in 2021. But the city also has four 19th-century village cores protected as heritage districts: Unionville, Markham Village, Thornhill and Buttonville. So a Markham glass job is usually one of two things, a fogged sealed unit in a 1980s to 2000s house, or a broken pane in an older sash in one of the village cores.
Either way the fix is usually new glass in the frame you already have, and Markham makes the heritage case easier than most owners expect. Within the four districts, the City lists repair of broken window panes to original specifications as work that does not require a heritage permit, while removal and replacement of windows or doors needs a Minor Heritage Permit. Minor permits carry no application fee, but they still take time. Markham's district guidance puts the order plainly: it is better to maintain than to repair, better to repair than to restore, better to restore than replace.
Today 56% of Markham dwellings are single-detached, 14% townhouses, 6% semi-detached, 5% duplex and 18% apartments, and apartments of five or more storeys grew 28% from 2016 to 2021. The subdivisions from Markham's 1970s to 1990s boom have original sealed units that are now 25 to 45 years old, and typical sealed-unit life is 10 to 25 years, so fogged glass is the most common call in those areas. Cornell, designed as a new urbanist community in 1994 with building starting in 1997, is younger but not immune: a 25-year field study found 4.9% of sealed units had failed by year 10 and 7.9% by year 15.
OhMyGlass Window and Door Repairs replaces the sealed unit or pane and keeps the frame. For heritage sash we match the original glass so the repair stays within Markham's exemption. If a frame has failed, we will tell you it is a window-replacement job rather than a glass repair. Tell us when you get in touch if you are in a heritage district and we will quote a like-for-like repair.
What tends to fail, by part of Markham
Markham's growth came in a steep curve, from 114,597 people in 1986 to 338,503 in 2021, and the glazing follows it.
older wood sash, some single glazing. Broken panes, loose glazing and sash wear, with heritage rules in play. Unionville's Main Street still resembles the small town that developed from the early 1840s.
original double-pane sealed units, casements and sliders. Fogged units, stripped cranks and patio-door rollers.
vinyl windows and larger units, now showing early seal failures and thermal cracks. Most Cornell homes are townhouses, semis or detached houses with garages off rear lanes.
window wall and balcony doors. Early Canadian window-wall systems had sealed units that often fogged after only a few years, which led to tighter requirements.
the declaration decides who pays, so check it before booking.
Markham's heritage exemption for broken panes
This is the rule most Markham homeowners do not know about, and it is the reason a pane repair is usually the shortest route.
we replace the glass to match and keep the sash. No heritage permit is needed under Markham's exemption.
replacing the glass inside the existing frame is closer to repair than replacement. Confirm with Markham heritage staff if the window is visible from the street.
that is a window-replacement job, not a glass repair, and it needs a Minor Heritage Permit first.
no application fee, but they add time, so ask the City before you commit.
new glass in an existing frame does not change the opening and is generally treated as repair. We could not confirm Markham's rule for same-size whole-window replacement from the City's published guides, so check with Building Standards before enlarging or adding an opening.
Markham's climate and your glass
Markham is rated at 4,000 heating degree-days against 3,520 at Toronto City Hall, about 14% more heating demand. Recorded extremes run from −35.2 °C in January 1994 to 37.8 °C in August 2001.
sealants are six to eight times more permeable at 60 °C than at 20 °C, and temperature cycling is one of the main ageing drivers.
tighter windows can also raise indoor humidity, so keep bath and kitchen fans running through the winter.
that is a failed edge seal, and no amount of ventilation clears it. The sealed unit is replaced and the frame stays.
Where to go next in Markham
The service page that matches your job, and the nearby city hubs.
Frequently asked questions: Markham window repair
Do I need a heritage permit to fix a broken window in Unionville?
Not if you repair the broken pane to its original specifications. The City of Markham lists that as work that does not need a heritage permit in its four districts: Buttonville, Markham Village, Thornhill and Unionville. Removing and replacing the window or door is different and needs a Minor Heritage Permit. Minor permits have no application fee, but they add time, so ask the City before you commit.
Do I need a building permit to replace window glass in Markham?
New glass in an existing frame does not change the opening and is generally treated as repair. For whole windows, we could not confirm Markham's rule for same-size replacements from the City's published guides. Before enlarging or adding an opening, or replacing windows in anything other than a single house, check Markham's Guide to Building Permits or ask the Building Standards counter.
Why are the windows in my 1990s Markham house foggy?
Fog between the panes means the edge seal of the sealed unit has failed. Typical sealed-unit life is 10 to 25 years, and Markham grew from 114,597 people in 1986 to 338,503 in 2021, so a large share of its houses have original units now past that range. A new sealed unit in the existing frame usually fixes it.
My Cornell townhouse is in a condo corporation. Who fixes the windows?
It depends on your declaration. Ontario's default is that the corporation repairs common elements and owners repair their units, but the declaration can change that split. Check your declaration and ask your property manager before booking. This is general information, not legal advice.
Can you match the glass in an original sash?
Yes. On heritage sash we replace the glass to match the original so the sash stays and the repair stays within Markham's exemption.
Guides for this job
Local guide
Markham grew from about 56,000 people in 1976 to 338,503 in 2021, so most of its houses have factory-sealed double-pane units from the 1980s onward; when one fogs, a new sealed unit goes into the existing frame.
Single-detached houses make up 56% of Markham's dwellings and townhouses 14%; apartments of 5+ storeys rose 28% between 2016 and 2021 and are now about 16% of dwellings.
In Markham's four heritage districts, repairing broken window panes to original specifications doesn't need a heritage permit, but removing and replacing windows or doors needs a Minor Heritage Permit, which has no application fee.
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