building a greenhouse? free glass possibly available

If you are interested in building a greenhouse, there might be some free glass available. They have been replacing the windows in our 12 floor apartment complex on the outskirts of Philadelphia. Everyday I see the workers throwing the old windows (shattering them in the process) into a dumpster. The windows are 38" x 24", single pane. There is probably enough thrown away everyday to build a small greenhouse. If anyone is interested in the glass (before its broken), let me know and I could ask if it would be alright for someone to take the old windows.

There are also windows 4xs as large, but I think they are recycling those.

Jonathan