That sounds like bad news, but it usually isn't, because replacing glass almost never means replacing the window. Most of the time it means new glass set into the existing frame, a far smaller job than the word "replacement" suggests.
The repairs that really are repairs
If the glass is fine but the window won't open or won't lock, that's hardware. Balances, hinges, latches, and rollers can be serviced or swapped without touching the pane, and in older Portland houses, where wood swells through the wet months, a sticking window sometimes needs adjustment more than it needs parts.
Sliding patio doors are a common version of this. The glass is intact, but the door drags because the rollers underneath have worn down, and new rollers put it back on track without any glass work at all.
Light surface scratches can sometimes be polished out with the right compound. Deep ones can't. Once a scratch catches a fingernail, it's in the glass for good, and whether that justifies new glass comes down to where the window sits and how often you find yourself looking at the mark.
When the glass itself is done
Cracked glass gets replaced, and so does shattered glass. Tempered safety glass, the kind in entry doors and patio sliders, is built to break apart completely rather than crack, so when it goes there is nothing left to repair.
A cracked pane that's still holding together buys you some time, but not unlimited time. The crack has already taken most of the pane's strength, and temperature swings keep working on it, so it belongs on the calendar even if it doesn't belong on today's to-do list.
Fog or condensation trapped between the panes of a double-pane window means the seal on that unit has failed, and it puts you in replacement territory too, though only for the glass, not the window. How to confirm it and what the options look like is covered in our foggy windows guide.
New glass or a whole new window
The frame makes this call. If it's solid, square, and keeping the weather out, new glass goes into it and the job is done, whether that's a single pane or a sealed double-pane unit, and the wall around the opening is never touched.
If the wood has gone soft where it meets the sill, or the frame has twisted enough that the sash binds, the frame is the real problem and the glass is only the visible part of it. Water finding its way in around the edges points the same direction. Portland's long wet season is hard on wood frames, and setting fresh glass into one that's failing buys a year or two at best before the window has to be dealt with anyway. When that's what an estimate visit turns up, we say so and quote the whole window instead.
The age of the window matters less than people expect. A wood window from the 1920s with a sound frame is a better candidate for new glass than a vinyl window from the 1990s with a cracked sill, because the condition of what's holding the glass outweighs the year it went in.
When you'd rather not guess
Most of this sorting takes a trained eye about five minutes in front of the window, which is faster and more reliable than an afternoon of internet research about your specific crack.
Call (503) 887-8329 and describe what broke and how the window behaves. You'll get a free written estimate that names which job yours is, and if it turns out to be a hardware fix, that's what the paper will say. The estimate costs nothing whichever answer it turns out to be.
Clear Works Glass works out of SE Portland, Monday to Friday 7 to 5, Saturday 8 to 2, with a 24/7 emergency line. Oregon CCB #261682, bonded and insured.