I got a quote for $800 for a single-glazed glass interior insert (32x48) but I'll ask around locally as I think plexiglass would be a lot easier to manage. Thanks, people!
We are renting a 10 year old house that backs up to a freeway. It has no- name dual pane vinyl windows. I'm offering to the owner to pay to replace the 2nd story master bedroom window, as the road has a steep grade here and the weekend morning motorcycles make quite a racket. 36" x 48" single...