Answer: Building and maintaining a greenhouse is a complex project beyond the scope of this simple Q&A service. I would suggest you take a look at the information at the following web sites and perhaps work with your local county extension for more locally-based information as to the best most economical design, construction materials and heating fuel. If you are planning to do this on a commercial basis your extension office should be able to assist you with that as well. You may need to cut and paste the complete url into your browser to make it work correctly.
Best of luck with your project!
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