Not every damaged or stained pane needs to be replaced, and not every stain can be restored. The decision comes down to how deep the damage sits in the glass, and a straightforward cost comparison once that's known.
Almost all glass staining and etching in Metro Vancouver traces back to mineral deposits left behind after water evaporates from the surface — irrigation overspray, wind-driven rain carrying salt or road grime, concrete or precast run-off, or sprinkler contact. See our hard water stain prevention guide for the full chemistry. The damage gets worse the longer the mineral deposit sits on the glass before being removed, because the deposit slowly bonds to and, eventually, etches into the glass surface.
Physical damage — scratches from improperly used squeegees or blades, sandblasting from nearby construction, or acid rain exposure near industrial areas — follows a similar logic: shallow damage is often correctable, deep damage usually is not.
This staging framework, common in the glass restoration trade, is the fastest way to set expectations before a technician is on site.
| Stage | Appearance | Restorable? |
|---|---|---|
| Stage 1 | Light mineral film or hard water spotting on the surface. | Yes — routine cleaning or light polishing usually resolves it. |
| Stage 2 | Visible spotting with early mineral bonding to the glass surface. | Yes — mechanical polishing or acid-safe restoration compound typically removes it. |
| Stage 3 | Heavy scale, visible haze, or light etching under certain light angles. | Often — professional restoration can improve it significantly, may not fully eliminate all haze. |
| Stage 4 | Etching into the glass surface itself; permanent structural change to the glass. | No — restoration cannot reverse structural etching; replacement is the only full fix. |
Restoration is priced per panel based on the size of the affected area and the amount of mechanical work needed to correct it — typically a fraction of the cost of sourcing, fabricating, and installing a replacement unit, especially where custom sizing or higher floors requiring rope access or lift work are involved.
That advantage narrows or disappears once damage reaches stage 4, or once a unit's seal has already failed for an unrelated reason (in which case restoring the surface of a unit that needs replacing anyway is wasted spend). It also narrows on buildings with standard, readily available window sizes, where a single-unit replacement is comparatively inexpensive and fast to source — sometimes making replacement the more practical choice even at stage 2 or 3 if the unit is due for other reasons.
The practical rule: get a stage assessment first, then price both options for the specific panel before deciding. Treating "restoration is always cheaper" as a rule of thumb leads to spending on panels that needed replacement anyway.
Before committing to a building-wide restoration program, test on one or two representative panels — ideally one showing moderate (stage 2–3) damage and one showing the worst damage on the building. A qualified technician should attempt restoration on a small, discreet section first to confirm the compound and technique won't damage any coating, and to give an honest before/after comparison you can use to decide on the rest of the building.
If the test section doesn't show meaningful improvement, that's the answer: move to replacement planning for that elevation rather than committing a full restoration budget to panels that won't respond.
Nearly every stage 4 case started as an untreated stage 1 or 2. Routine cleaning on an appropriate frequency (see our frequency guide) prevents mineral deposits from sitting long enough to bond and etch. Where irrigation or run-off exposure is unavoidable, protective coatings and adjusted irrigation aim, covered in our hard water prevention guide, are materially cheaper than any restoration program.
Fine surface scratches from squeegees, blades, or debris can often be polished out if they don't penetrate deep into the glass surface. Deep scratches, chips, or scratches that catch a fingernail typically cannot be fully removed without leaving an optical distortion, and replacement is usually the better outcome.
No. Restoration is typically cheaper per panel for stage 1–3 mineral or chemical damage. Once damage is stage 4 (etched into the glass structure) or the unit's seal has failed, restoration cost can approach or exceed the cost of replacing a single unit, especially on standard-sized residential strata windows where replacement units are readily available.
It can, depending on the manufacturer and the coating type. Low-E and other coated glass is more sensitive to abrasive restoration methods. Always confirm warranty terms and coating type before authorizing restoration work, and use a contractor who tests on a discreet panel first.
Stop stage 1 damage from ever becoming a restoration or replacement decision.
Read more →The frequency that keeps mineral deposits from progressing past stage 2.
Read more →Get a stage assessment and a priced comparison of restoration vs. replacement.
Read more →Send us photos of the affected glass and we'll tell you honestly whether restoration is likely to work before you commit to either option.