Windows in Austin are a sun problem that becomes a comfort problem on the freeze night. West and south glass loads the house all through the long heat. Older single panes in Hyde Park, Travis Heights, Clarksville, and similar bungalows leak air so the room near the window is miserable when the cold snaps. Newer walls of glass do the same job faster. Hail can crack a light, but the daily complaint is heat and a frame that was never meant to seal.
Sort the symptom. Condensation on the inside of a cold pane during a freeze is moisture from the room, not a failed seal. Fog between two panes means the seal is done and the glass is finished even if it never cracked. A wet stool after a hard rain is flashing or a rotten sill, common where stucco or limestone meets an old frame. Wipe tests tell these apart. A new unit in a soft opening will leak in the next gully-washer.
Talk about the wall, not a catalog. Deep bungalow trim, stone, and stucco each need a flashing sequence and a sill that can drain. Forcing a flanged unit into an old opening without that work repeats the leak and the draft. If the glass is large and west-facing, say so, because the cooling load is part of why you are calling.
Hardware swells and sticks in the humid weeks, then the same sash rattles when a north wind hits on the cold night. Locks that do not meet and balances that drop are repairs. A crack from a limb or from hail is a glass repair or a sash repair. Say which you have so the visit brings the right parts. Photograph the opening before anyone caulks it. Caulk over a bad sill is how water stays in the wall.
Count the windows that bake, leak air, fog, or leak rain, and name the walls. Say bungalow or new construction so the opening type is clear. Have the address ready. Ask for a repair of glass and hardware or a full unit set in a flashed opening, whichever matches the failure. Call the number on this page.