I'd start with a google search for greenhouse vendors. Most have information pages that provide information on things like foundations, heat retention, site selection, etc. A budget of $1500 will limit your choices. Some greenhouses can be pretty expensive. Also, consider if you are handy enough to assemble a kit. I have a Solexx greenhouse and am very happy with it. But the panels do not allow viewing in or out of the greenhouse. If that is important to you a different model would be better. A little planning up front will result in a more satisfied purchase. Good luck!
