Instructables website shares how to build a greenhouse using old recycled windows.
Do you have a neighbor who was replacing all the windows in their house, sometimes you can find free windows on craigslist or a visit to local Habit For Humanity store for small cost.
Glass also looks nice, is simple to clean and the windows can be opened to release heat if needed.
Click here to read how you can make this project yourself:
http://www.instructables.com/id/Greenhouse-From-Old-Windows/
