# Foggy Window Repair Toronto | IGU Replacement > Foggy windows? We replace failed insulated glass units (IGUs) and repair drafty, hard-to-operate windows across the GTA. Book an inspection. URL: https://torontoqualitywindows.ca/window-repair-foggy-igu/ ![Foggy window with condensation trapped between the panes in a GTA home](/images/misc/foggy-window-with-visible-condensation-trapped-bet.webp) Lower-Cost Fix # Foggy Window & IGU Repair Across the GTA Last updated: August 9, 2026 Repair of foggy, drafty and failing windows, including insulated glass unit (IGU) replacement, before you commit to full replacement. - Energy Star Zone C - In-house crews - 10-Year Labour Warranty Get a Free Quote [/contact/ →](/contact/) (437) 524-9688 [tel:+14375249688 →](tel:+14375249688) Starting at $ 300 per glass unit (typical) - 4.9 / 5 150+ Google reviews - Energy Star Zone C Certified for Climate Zone 6 - In-House Crews No subcontractors, WSIB insured - 10-Year Labour Warranty Plus manufacturer warranties ## Why Your Windows Have Gone Foggy A modern window’s insulating work is done by the **insulated glass unit (IGU)**: two or three panes held apart by a spacer bar and sealed around the perimeter. That cavity holds an **argon gas fill**, and at least one glass surface carries a **Low-E glass** coating. Sealed correctly, that assembly stays clear and efficient for two decades or more. **Thermal seal failure** is what ends it. Every day the unit heats up, expands, cools and contracts. Over 15 to 25 years, faster on south and west elevations that take the most sun, the perimeter seal degrades. Once it breaches, the argon escapes and humid outdoor air moves in. The desiccant in the **warm-edge spacer** absorbs that moisture until it’s saturated, and then condensation starts forming on the inner glass surfaces where you can’t reach it. That’s the milky haze, and the white mineral staining that follows it. The important part: the frame, the sash and the hardware are usually fine. Only the glass unit has failed. That is why a foggy window is often a repair rather than a replacement, and why we quote it as a glass swap before we quote it as one of our window and door replacement projects in the GTA [/ →](/) . ![Technician lifting a failed insulated glass unit out of its vinyl sash](/images/misc/technician-lifting-a-failed-insulated-glass-unit-o.webp) ## Repair or Replace? The Honest Comparison We quote both numbers and let you choose. Here’s how the decision usually goes. | Situation | Recommended | Typical cost | | --- | --- | --- | | Failed seal, frame sound, hardware good | Glass unit swap | $300 – $700 per unit | | Drafty, sticking, won’t lock; glass fine | Hardware & seal repair | $150 – $450 per opening | | Rot at the sill, racked frame, water staining | Full window replacement | $600 – $1,200 per window | | Most of the house failed at once | Whole-home replacement | $8,000 – $18,000 | A **glass unit swap** restores clarity and brings the **U-factor** back near its original figure, because the replacement unit carries the same Low-E coating, argon fill and warm-edge spacer specification as a new window. What it can’t fix is a worn frame, so if the sash has sagged past adjustment or there’s moisture damage in the buck, we’ll say that the money is better spent on window replacement [/window-replacement/ →](/window-replacement/) instead. ### Common Problems We Solve #### Haze and staining between the panes The classic failed IGU. We confirm it’s genuinely a seal failure rather than surface condensation, measure the sash rebate, and fit a new sealed unit. #### Cold draft from a closed window Almost always a compression problem. If the lock doesn’t fully engage, the sash isn’t being drawn tight into its weatherstripping, so the **air leakage rate** through that opening stays high even when it looks shut. New weatherstripping and a lock adjustment fixes it. #### Casement cranks that grind or won’t close Operators and hinges wear out long before the frame does. Replacing the hardware is straightforward and restores proper closing pressure. #### Condensation on the inside surface in winter This one usually isn’t the window. Interior surface condensation means indoor humidity is high relative to the glass temperature. Better glass, meaning a higher **condensation resistance (CR) rating**, helps, but so does managing humidity. We’ll tell you which is actually your issue. ## What About “Defogging”? You’ll see services offering to drill a failed unit, dry it out and fit a vent. It clears the visible haze for a while. It does not restore the perimeter seal, does not restore the argon fill, and leaves the cavity permanently vented to outside air, so the insulating performance stays degraded and the haze often returns. We don’t offer it. Replacing the sealed unit costs more up front and is the fix that actually lasts. ## Book a Diagnosis Visit We come out, confirm opening by opening whether the seal has genuinely failed, check the frame and hardware condition, and give you both numbers in writing: repair and replace. There’s no charge for the assessment and no pressure toward the bigger job. \[ Investment Ledger \] ## How Much Does Window Repair Cost in the GTA? Oversized, tempered, laminated or decorative glass units sit above the typical range. Code: R-IGU Most Requested ### Glass Unit Replacement Failed seal, sound frame: the most common fix. - Failed IGU removed and measured - New sealed unit with Low-E and argon - Warm-edge spacer - Warranty on the replacement unit Installed $300 – $700 Code: R-HDW ### Hardware & Draft Repair Sticking sashes, worn seals, locks that won't engage. - Weatherstripping renewal - Hinge, crank and lock replacement - Sash adjustment and re-squaring - Air leakage re-test on close Installed $150 – $450 Code: R-DIA ### Diagnosis Visit Honest repair-or-replace assessment, in writing. - Seal failure confirmation per opening - Frame and sill condition check - Repair vs replace cost comparison - No obligation Installed Free with quote ### What Moves the Price **Opening size and count.** Larger units cost more per opening, and whole-home projects carry a lower per-window install cost than a single replacement. **Glazing package.** Double versus triple glazing, coating count, gas fill and laminated or tempered safety glass all move the number. **Installation method.** Retrofit inserts cost less than full-frame brick-to-brick work, which adds roughly 25% but corrects hidden damage. **Shape and finish.** Arched heads, bays, custom colours and matched sightlines across an elevation all sit above standard rectangular openings. Every quote is itemised per opening, so you can see exactly where the money goes and adjust the scope room by room. Book a free in-home measurement [/contact/ →](/contact/) . \[ Differentiators \] ## Why Choose Toronto Quality Windows for Window Repair? ### We'll Talk You Out Of It If the frame is sound, a glass unit swap costs a fraction of replacement and gets you most of the performance back. We say so, even though the bigger job pays us more. ### Correct Diagnosis First Not every foggy window is a failed seal. Interior condensation, exterior dew and surface film all look similar from a distance. We confirm which before quoting anything. ### Same Glazing Spec Replacement units carry Low-E coating, argon fill and a warm-edge spacer, so the repaired window performs like a modern one rather than like plain glass. ### Warranty On The Work Replacement sealed units are warrantied, and our labour is backed the same way as our installation work. WSIB insured, CSA A440 compliant. \[ Method \] ## How Does Window Repair Work? 1. 01 ### Diagnosis Visit We inspect each affected opening, confirm whether the seal has actually failed, and check the frame, sash and hardware condition. 2. 02 ### Repair or Replace Call You get both numbers in writing (glass unit swap versus full window replacement) so the decision is yours with the real figures in front of you. 3. 03 ### Precise Measurement Sealed units are made to the millimetre. We measure the sash rebate and record the glazing build-up so the replacement drops in cleanly. 4. 04 ### Unit Swap The failed unit comes out, the rebate is cleaned, and the new sealed unit is bedded on fresh glazing tape with new beads. Most openings take under an hour. 5. 05 ### Function Check We re-test operation, locking and compression on every repaired window before we leave, and register the warranty on the new units. ## Not Sure If Window Repair Is the Right Call? Book a free in-home measurement. We'll give you a written recommendation, itemised pricing per opening, and nothing gets ordered until you approve the spec. (437) 524-9688 [tel:+14375249688 →](tel:+14375249688) Book a Free Measure [/contact/ →](/contact/) ## How Toronto Quality Windows Compares | Feature | Typical Provider | Toronto Quality Windows | | --- | --- | --- | | Typical cost per opening | Full replacement quoted by default | $300 – $700 glass unit swap where viable | | Diagnosis | Visual guess at the door | Per-opening seal confirmation | | Replacement glazing spec | Plain sealed unit | Low-E, argon, warm-edge spacer | | Time on site | Full install day | Under an hour per opening | | Repair-vs-replace advice | Replacement only | Both options priced in writing | \[ Project Record \] ## Our Window Repair Work Click any image to enlarge. \[ Client Record \] ## What Customers Say About Our Window Repair Rated 4.9 out of 5 across 150+ reviews. > "We had foggy glass in three windows. Instead of pushing a full replacement, they swapped just the glass units and saved us a lot. Honest and knowledgeable." Priya S.Mississauga > "Five windows had fogged up. They replaced just the glass units and the house looks new again. Fast and fairly priced." Manpreet K.Springdale, Brampton > "Two windows facing the lake had failed seals. Rather than sell me a full replacement, they changed the glass units. Saved us thousands." Sofia N.Mimico \[ Objections Handled \] ## Window Repair FAQs ### Why do windows go foggy between the panes? The insulated glass unit is sealed at the perimeter to hold an argon gas fill and keep moisture out. Over time, usually 15 to 25 years and faster on hot south-facing elevations, that seal degrades. Once it breaches, the argon escapes, humid outdoor air gets in, and moisture condenses on the inner glass surfaces. The haze and mineral staining you see is the visible result. ### Can foggy windows be fixed without replacing the whole window? Usually yes. If the frame, sash and hardware are sound, we replace only the failed insulated glass unit. It costs a fraction of full window replacement and restores both clarity and most of the original insulating value. ### How much does foggy window repair cost? A typical sealed glass unit replacement runs $300 to $700 per unit. Oversized, tempered, laminated or decorative units cost more. Compare that to $600 to $1,200 for a complete window replacement and the case for repair is usually clear. ### Is 'defogging' a real fix? Drilling and drying a failed unit can clear the visible haze temporarily, but it does not restore the seal, the argon gas fill or the original insulating performance, and the unit stays vented. We don't offer it. Replacing the sealed unit is the durable fix. ### How do I know if it's a failed seal or just condensation? If the moisture is between the panes and you can't wipe it off from either side, the seal has failed. Condensation on the inside surface is a humidity issue in the room; moisture on the outside surface on a cool morning is normal dew and means the glass is insulating well. ### How much insulating value do I lose with a failed seal? Once the argon escapes, the cavity fills with air, and the U-factor drops back toward a plain double-pane value. If moisture has also degraded the Low-E coating, performance falls further. It isn't catastrophic, but on a whole elevation of failed units it's noticeable through a Toronto winter. ### When is full replacement the better call? When the frame is rotted, the sash has sagged past adjustment, the hardware is obsolete, or a large share of the home's units have failed at once. At that point you're repairing a component inside a worn-out assembly, and putting the money toward window replacement makes more sense. ### Can you fix drafts and windows that won't lock? Yes. Weatherstripping renewal, hinge and crank replacement, lock and keeper adjustment and sash re-squaring are all routine work for us. A window that won't lock cleanly isn't compressing its seal either, so it's leaking air even when closed. ### How long does a glass unit replacement take? Most openings take under an hour once the replacement unit is on site. Manufacture of the sealed unit takes some lead time after measurement, which we confirm when we book. ### Do the new glass units come with a warranty? Yes. Replacement sealed units carry a manufacturer warranty and our labour is backed the same way as our installation work. ### Still have a question? Ask us during your free in-home measurement, or get in touch and we'll answer it straight. Get a Free Quote [/contact/ →](/contact/) \[ Also Consider \] ## Related Services ![Installer fitting a new triple-pane vinyl window into a brick opening on a Toronto home](/images/misc/installer-fitting-a-new-triple-pane-vinyl-window-i.webp) ### Window Replacement Supply and in-house installation of vinyl, casement and triple-pane windows certified to Energy Star Zone C. Learn more [Window Replacement →](/window-replacement/) ![European tilt-and-turn aluminium window tilted open in a bright Toronto living room](/images/misc/large-european-tilt-and-turn-aluminium-window-tilt.webp) ### European Tilt-and-Turn Windows Authorized European tilt-and-turn window systems from Schuco, Reynaers and Cortizo with best-in-class thermal and security performance. Learn more [European Tilt-and-Turn Windows →](/european-tilt-and-turn-windows/) ![](/images/misc/installation-crew-finishing-a-row-of-new-windows-o.webp) Free in-home consultation across the GTA ## Ready to Book Window Repair? Free in-home measurement, itemised pricing per opening, and a written specification before anything is ordered. Get a Free Quote [/contact/ →](/contact/) (437) 524-9688 [tel:+14375249688 →](tel:+14375249688) - 10-year labour warranty - In-house crews, never subcontractors - Energy Star Zone C certified