Hi Folks:
I've enjoyed reading this thread. Whimgrinder and others have made excellent suggestions on how to run a small hobby house but in the end you need to get in there and figure out what works and doesn't, probably after spending a bit of money and time and reinventing the wheel.
To truly run a small hobby house in working condition where the plants will grow properly figure you will sped the equivalent of buying a good used car, or perhaps even a new one. I'm not joking. You might seriously consider that your money is better spent on lights and a series of terrariums in a climate controlled house. Therein lies the rub. Small hobby houses are notorious for their difficulty in controlling climate because of their large surface area relative to the volume of air inside.
We have a 10 x 20 glass/aluminum greenhouse and it has taken us about 10 years to get it really cranking and working to perfection (we went through the bubble wrap phase to hold expensive propane heat). Key items: concrete slab floor with drains for ease of ceaning and hygiene, electrical upgrade @200 amps $1000, various heating systems from 2, 25,000 Btu propane heaters at $500 each with annual operating cost of $2000/year at 65-70F, upgraded heating system to outside wood furnace heating house and greenhouse - $14,000 which is paying for itself versus cost of propane, growing benches @several thousand dollars built by us of wood, plumbing done by us for both clean potable water and pond water, instant water heat @ $500, T5 and HPS lights $2000, evaporative cooler @$500, shade cloth @$200.
Well that's a good start at your initial expense getting the greenhouse to do what it should do. Not childs play.
Sincerely,
Phil Sherida, Ph.D.
Director
Meadowview Biological
Research Station