Most LA window problems don't need replacement — they need repair. A stuck sash, a torn screen, a foggy IGU, a busted crank: every one of these is a $100–$500 repair, not a $1,500–$3,000 replacement. The working test that decides which path your window needs runs through three checks: the frame test, the operator test, and the insulation test. Here's how to run it.
Test 1: The frame test
Look at the window frame from inside and outside. Push gently on the frame edges. If the frame is solid, sealed at the perimeter, and not visibly rotted or split — the frame is fine. The window can be repaired.
If the frame is rotted, split at the corners, separated from the perimeter caulk, or showing visible mold/water staining inside the frame channels — the frame is the problem. At that point you need replacement, because every repair you do to the moving parts will be undermined by a failing frame.
Test 2: The operator test
Operate the window through full travel. A double-hung should slide up and down smoothly; a casement should crank fully open and closed; a slider should glide on its track.
If the operator (balance, crank gearbox, slider rollers) is the problem and the rest of the window works — that's a repair. Replacement parts for almost every consumer-grade window made in the past 30 years are still available, and a swap is straightforward.
If the operator is fine but the sash itself binds against the frame, won't seal, or has visible warp — that's a sash problem. Sash replacement is sometimes possible but often crosses into full window replacement territory.
Test 3: The insulation test
If the window is double-pane (most LA windows from 1990 onward) and shows fogging or condensation between the panes, the IGU seal has failed. The frame is fine; only the glass package needs to come out and be replaced. This is a repair, not a replacement — IGU swap runs $185–$485.
If the window is single-pane and the homeowner wants energy efficiency, that's a replacement decision, not a repair decision — there's no upgrade path that turns a single-pane window into a double-pane without replacing the unit. Most LA homes built before 1980 have single-pane glass.
When replacement is the right call
Frame is rotted or compromised. Multiple operator and sash failures combined with frame issues. Single-pane windows being upgraded for energy efficiency, soundproofing, or modern aesthetics. Homes being prepped for sale where window appearance matters more than original character.
Red Stag does NOT do full window replacement — that's our sister company, Red Stag Windows & Doors (redstagwindows.com). If you call us and we determine your job is replacement-grade, we diagnose on-site, take measurements, and refer you over with the data already collected.