i am growing warm growing orchids mainly in my house by a window. i put them in the greenhouse on nice days and through the summer, but my greenhouse is a simple glass thing, with small gaps in. when i move out i want a brick and glass greenhousewith heating
best to just use a thermometer and check what temperatures you have, if your getting a greenhouse ask how good it is at insulating etc. you could put heaters in there but unless its insulated its a waste.