| Scope | Estimated range |
|---|---|
| 24 x 36 in | $240 – $480 |
| 30 x 48 in | $300 – $590 |
| 32 x 60 in | $350 – $700 |
| 36 x 72 in | $430 – $900 |
| Argon fill add | +$15 – $45 / unit |
Ranges reflect installed cost including materials and labor for typical residential work. The low end of each range corresponds to a basic vinyl configuration; the high end reflects premium frames, upgraded glazing, and larger units. Last reviewed 2026-11-12.
Two panes of glass with a 1/2-inch argon gap insulate far better than two panes with a 1/4-inch air gap. The gas fill and gap width are what the U-value actually reflects, and both are invisible once the unit is built.
A double-pane unit does not wear out by cracking; it fogs when the perimeter seal fails and moisture enters the gap. Once fogged, the unit must be replaced, and the frame is usually still fine, which is why glass-only replacement exists as a service.
The metal spacer around the glass edge conducts heat and shows up as condensation or frost along the perimeter. Warm-edge spacers (stainless steel, silicone foam, or butyl) cost slightly more and eliminate that stripe.
They are the same thing. Insulated glass unit (IGU), double-glazed, and double-pane all describe two panes separated by a sealed gap. The terms are interchangeable in the industry.
The only real repair is replacing the sealed unit, not the whole window. Defogging by drilling and drying is a temporary patch that usually fogs again, and it voids the unit's seal.
Manufacturer seal warranties commonly run 10-20 years. Real-world seal life depends on sun exposure, thermal cycling, and installation quality; south and west facing units in high-swing climates tend to fail first.