(Egress window: a window that is large enough to meet code locally for an adult person being able to escape from the house through the window in case fire or other emergency blocks the exit. Needed to make a room into a bedroom rather than a "study" or "den." Ever wonder why a room that looks like a bedroom and is decorated like a bedroom is advertised as a den? Window(s) may be too small to get out in case of emergency. Sometimes there are other factors, but that's one.)
ETA: Got some people tracked down for bids. Thanks, everybody; much appreciated.