How an IGU swap works
Dual-pane windows hold a sealed insulated glass unit (IGU). Replacing one is a contained job that leaves the frame, trim and stucco alone.
- The installer measures the existing glass and notes its thickness, spacer and whether it must be tempered.
- A new IGU is ordered to size, usually with low-e glass at least equal to the old unit.
- On the return visit, the glazing stops or sash are removed and the old unit comes out.
- The new unit is set on setting blocks, sealed with glazing tape or sealant, and the stops go back on.
- The installer cleans up and hauls away the broken glass.
On many sliders and single-hungs, the whole sash comes out and goes to the shop instead. Either way, measuring and installing are typically two separate trips because the glass is made to order.
Broken, cracked or fogged glass
Broken or cracked
Tape the crack or cover the opening and keep people away from loose shards. A crack in one pane of a dual-pane unit still means replacing the whole sealed unit, because the panes are bonded to a common spacer.
Fogged between the panes
Haze or droplets you can't wipe off from either side mean the edge seal has failed. The glass isn't dangerous, but the insulating value has dropped and the haze won't go away. A new IGU fixes it. Our double-pane windows page explains why seals fail and when replacing the whole window makes more sense.
Sliding glass door glass
Sliding door panels can often be reglazed, but the glass must be tempered and the panel is heavy. If the rollers, track or frame are also failing, compare the price of a full sliding glass door replacement.
Where tempered glass is required
The residential code requires safety glazing (usually tempered glass) in "hazardous locations." The list below follows the 2018 IRC R308.4 sections; California's current residential code section numbers weren't confirmed, so let the installer and your building department have the final word.
- Glass in swinging, sliding and bifold doors, including every sliding patio door.
- Glass within 24 in. of a door whose bottom edge is less than 60 in. above the floor.
- Large panes that meet all four conditions: over 9 sq ft, bottom edge under 18 in. above the floor, top edge over 36 in., and a walking surface within 36 in.
- Glazing in guards and railings.
- Glass near tubs, showers, spas and pools with its bottom edge under 60 in. above the standing surface.
- Glass next to stairs and ramps, and near the bottom stair landing.
Tempered glass carries a small permanent mark in one corner. If your existing pane has one, the replacement needs one too. If a pane in one of these locations isn't tempered today, replace it with tempered glass anyway.
How Title 24 treats glass replacement
California's energy code says glass replaced in an existing sash and frame, or sashes replaced in an existing frame, are repairs, provided the replacement is at least equivalent to the original in performance. In practice, that means the 2026 new-window limits (U-factor 0.27 and SHGC 0.23 in Climate Zones 11 and 12) don't govern a glass swap, but you shouldn't go backward: if the old unit had low-e glass, the new one should too.
Whether a glass-only repair needs a permit varies by jurisdiction. Unincorporated Sacramento County requires a permit to replace windows (retrofit or cut-in), and most nearby cities expect one for window replacement; check with your local building division about glass-only work. For full window replacement rules, see energy-efficient windows.
Glass replacement cost
These figures come from a search summary of national cost guides, not Sacramento quotes, so use them only as a rough check.
| Job | Typical national range |
|---|---|
| Standard double-pane glass panel | About $150–$400 |
| Window glass replacement, overall | About $250–$1,000 |
| Full new window, installed (Fixr average) | About $800 |
Tempered glass, large or odd-shaped units, grids between the glass and second-story access raise the price. If the glass quote is close to the cost of a new window, a new window usually wins. See window replacement cost in Sacramento.
Hiring for glass work
In California, a C-17 Glazing contractor is licensed to cut, assemble and install glass, sashes and frames. Check the license at cslb.ca.gov. Jobs under $500 total in labor and materials don't require a license, but a tempered patio-door panel or a set of IGUs often goes over that. On a contract, the down payment can't exceed $1,000 or 10% of the price, whichever is less. For the bigger picture, start with window replacement in Sacramento.
Main guide: window replacement in Sacramento.