I live in a 1958 "modernist" townhouse. It is pretty modest but was designed by a well-known architect (I. M. Pei). The windows (original) are in bad shape and need to be replaced, but I am not clear what my options are. All the windows are the same size (6' long x 5 feet high). These are "picture windows" that do not open. Beneath the big windows are smaller ones that are 2' x 5' that slide open. There are 4 windows on the front, 2 on the first floor, 2 on the second, and in the back of the house, there are two on the second floor and then a giant glass wall with a door that overlooks the backyard.
As it stands the windows don't allow for much ventilation since only the smaller, floor level windows open and only for 1/2 the length. Is it possible to get a casement or awning type window in 6 x 5 that would allow for better ventilation? Some of my neighbors have replaced their smaller sliding windows with the kind that pop out, but I am not sure if more air can get in this way or not. Any suggestions or advice?