Hi, all, someone have a tropical >18C greenhouse in a zone 8 9 country, what are the cost of mantineance in winter ?

18C is roughly 65F. That is unattainable in a large greenhouse. It is attainable in a small one though. How large are you wanting to build? My greenhouse is 1730 sq ft. I have a commercial grade propane heater that I set at 60F in winter. Setting it at 6o will keep MOST of the GH at 55-58F at night when we have temps in the 20's-30's. Temps in extreme corners may fall to 47-48 due to heat distribution being uneven. Propane is not cheap. I may spend almost $2000 on propane if winter is harsh, $500 if mild. This has been a harsh winter. The 3 years BEFORE this were mild. Its variable. And electricity is another bill, to run fans and such

What a wonderfull greenhouse Thanks a lot for precius information Gina, i want a smaller one like 400sqft but in winter here there is 30 40 farenight and energy in europe cost much more than us so i m doing some count if it s more convenient a make a custom one with double or triple glass also because i m bit worried about snow fall, snow 4 or 5 time a winter 20 50cm.

We would never have been able to afford real glass. Its extremely expensive here, and the laws and closed around building with glass can require an architect drawn design. The problem here that is larger that cold protection in the winter (because the winter here is very short and mild, no ice, no snow) is cooling in summer. Th intense heat and humidity cam make cooling a challenge

i have full sun position but i can use big tree for shade becouse my space would be on hill and i ve same problem i can t do foundation due to law regulation but i m more worried about heating here winter gestione from mid november to late march with 0 10 so long and snow destroy everytime also my steel bersot that s why i m worried and asking for experience I think your climate can be like mid italy, like tuscany, bit more humid where frost are rare, in northern italy it s bit cold, i ve alps at 40 km. thanks again Gina for all suggestion