Deciding on a fix
New glass, a restored sash or a new window: deciding for a Kingston house
If the frame is sound, fix the part that failed: a fogged or cracked thermal unit can be replaced on its own, and old wood sash can often be restored and paired with storm windows. Replace the whole window when the frame is soft, out of square or leaking, or when several things fail at once. Ontario's rebate pays only for complete ENERGY STAR replacements, so don't let it decide for you.
The frame decides: sound, tired or failing?
Before anyone talks about glass, look at what holds it. The frame and the sash (the part that opens and carries the glass) tell you which conversation you're having.
- Sound. Square, dry, firm to a screwdriver at the corners, and it opens and locks. Whatever failed is a part: the glass, a crank, a balance. Fix the part.
- Tired. Paint and putty gone on a wood sash, cracked caulking outside a vinyl frame, drafts where the sash meet. This is maintenance, and worth doing before anything bigger.
- Failing. Soft wood, corners pulling apart, water stains below the sill inside, or a bowed frame the sash won't close against. New glass would go into a frame on its way out.
On stone and brick houses, check the outside sill too: the joint where wood meets masonry is where water gets in.
Problem by problem: fog, cracks, drafts, hardware and rot
Here is what each symptom usually means. The pro you're matched with confirms it on site.
A quick decision table
| What you see | Usually failed | Usually fixed by | Points to a new window when |
|---|---|---|---|
| Haze between the panes | The thermal unit's seal | A new thermal unit | Several units fog in a soft or leaking frame |
| A cracked pane | The glass | New glass or a new unit | A shifting frame caused the break |
| Draft at the sash edges | Weatherstripping | New weatherstripping, adjusted hardware | Air comes through the frame itself |
| Crank spins, sash won't stay up | Operator or balance | A replacement part | No parts exist for that window |
| Soft wood at a sill corner | Rot where water sits | A local wood repair | Rot runs along the sill or frame |
Water on the room side that wipes off is condensation, not a failed unit; foggy thermal units explains the difference. Cranks, balances and locks are covered under window repair.
Two kinds of Kingston house, two usual answers
The old core, rebuilt in stone and brick after the 1840 fire, still has plenty of wood sash with storm windows over it. A large share of the rest of the city went up between the 1960s and 2000, mostly with thermal units in vinyl or aluminium frames, the generation whose seals are now giving out.
| Stone-and-brick core | Later suburbs | |
|---|---|---|
| Typical window | Wood double-hung sash, storms outside | Sliders and casements with thermal units |
| Common complaints | Sticking sash, loose putty, broken cords | Fog between the panes, worn rollers and cranks |
| Fix-the-part route | Restore the sash, reglaze, refit storms | New thermal unit, hardware or weatherstripping |
| When to replace | Rot through the frame | A warped frame, or most units failing together |
| Check first | Heritage status | Warranty paperwork |
Neither column is a rule. Many core houses got replacement windows long ago, and some suburban frames were badly installed from the start.
A new thermal unit or a whole new window
When only the glass has failed, a thermal unit swap is the smaller job. The pro lifts out the glazing stops (the strips that hold the glass), measures, and orders a sealed unit made to size, then fits it on a return visit. Frame, trim and paint stay as they were, which matters where plaster returns or deep stone openings would need refinishing after a full replacement.
A whole new window makes sense when the frame is the problem, when you want a different style, or when unit after unit is failing. It is also the only route that can earn a rebate. Replacement windows explains retrofit and full-frame installs.
What about defogging?
Defogging drills small holes, dries the space between the panes and reseals the holes, so a hazy unit looks clearer. It doesn't restore the original edge seal. Some owners accept that for one unit they mainly want to see through; others prefer a new unit. On a fairly new window, check the warranty first.
Old wood sash: the case for restoration
Wood sash from the 19th and early 20th centuries was built to be taken apart: glass held with putty and glazing points, cords and weights in boxes that open, joints that can be reglued. That makes restoration a practical repair, not a sentimental one:
- Reglazing replaces a cracked pane and dried-out putty.
- Re-cording frees a sash painted shut or hanging on a broken cord.
- Weatherstripping takes out much of the rattle and draft.
- Storm windows take the weather first and keep lake wind off the sash.
Rot into the frame, or sash rebuilt so often that little original wood is left, points elsewhere. Wood window and sash repair covers what a restorer checks, and storm windows covers the pairing.
Heritage homes: approvals, the City's window policy and grants
If the house is designated, or sits in the Barriefield, Market Square or Old Sydenham conservation districts, window work isn't only your decision. The City's heritage permits page says altering windows on a designated property needs a heritage permit, while Council-defined maintenance is exempt. The City's Window Renovations in Heritage Buildings Policy is available on request through MyKingston; read it for your own plan rather than relying on a summary. Designated owners may also qualify for the City's Heritage Property Grant. The limestone and heritage homes guide covers all of it.
Money: what rebates do and don't cover in 2026
- A glass-only repair earns no rebate. No current program pays for a new thermal unit in an existing frame.
- Ontario's Home Renovation Savings Program offers a rebate on complete ENERGY STAR certified windows and doors, generally as part of two or more upgrades with a home energy assessment. Check the terms at homerenovationsavings.ca.
- Better Homes Kingston, the City's loan and rebate program, is not accepting applications. Watch for a relaunch.
- Federally, the home-retrofit grant has closed, and there is no general window grant in 2026.
A rebate rarely changes the answer for one fogged unit in a good frame. Weigh it against the full cost of replacement, not against doing nothing.
What moves the quote on each path
We don't publish prices: every unit and window is made to measure. These are what move a quote.
- New thermal unit: size and shape; glass type, such as low-E, or tempered where the code calls for it; stops that lift out or a sash that must come apart; upper-floor access or a storm window in the way.
- Restored sash: how many sash, how much putty, paint and wood repair, whether cords or pulleys need work, and old storms refitted or new ones made.
- New window: retrofit or full frame out, frame material, stone sill condition, out-of-square openings, interior finishing, and any heritage matching.
Questions to ask the pro you're matched with
We connect you with an independent local pro who does the kind of work you need; they measure, quote and do the job. Worth asking them:
- What exactly has failed, and can you show me?
- Is the frame sound enough for a glass or parts repair?
- If you recommend a new window, why is the repair the weaker option here?
- What does the written quote include: removal, finishing inside and out, heritage paperwork?
- What warranty covers the glass, the product and the labour?
A contract signed at home carries a 10-day cooling-off period under Ontario's consumer protection rules. For a pro's view first, send photos with a quote request: the whole window, one corner close up, and the sill outside.
Frequently asked questions
When is replacing only the glass enough?
When the glass is the only thing that has failed. A fogged or cracked thermal unit in a square, dry, firm frame can be replaced on its own, keeping the sash, trim and paint. If the frame is soft at the corners or air moves around it, new glass is money spent on a window that's already leaving. Foggy thermal units explains the swap.
Is a thermal unit swap always the cheaper route?
For one fogged unit in a sound frame, it is usually the smaller job. It stops being the obvious choice when several units in the same window are failing, when the frame needs work too, or when the unit is an unusual shape. That's why the frame check comes first. If you're unsure, ask the pro to price both paths.
Can a thermal unit be fitted into an old single-glazed wood sash?
Sometimes, but not often. A sealed unit is thicker than a single pane, and many old sash don't have the depth to hold one without being rebuilt. That's why the usual arrangement on older Kingston houses is the original sash with a storm window outside, which gives two layers of glass without cutting into the sash. The pro can check the sash on site.
Can one unit in a bay window be replaced on its own?
Usually, yes. A bay is typically a centre unit and two angled side units, each with its own glass, so one fogged or cracked thermal unit can normally be replaced without touching the others. Replacing the whole bay makes more sense when the seat, roof or framing has water damage, or the units are failing together.
What does a defogging kit actually do to a fogged thermal unit?
It dries the space between the panes through small drilled holes, then seals them, so the glass looks clearer. It doesn't restore the original edge seal, so the unit insulates no better than it did after the failure. Some owners accept that for one unit; others prefer a new one. Check any warranty first.
