It is essential that the house be as tight as possible so that it retain both heat and humidity. Problems with overheating can usually be solved by simply opening the door. Supplemental heat can be provided if needed during very cold weather or at night by one or more heat lamps or a small electric heater. Any electrical devices used in the damp environment of a greenhouse should be connected only to a circuit equipped with an approved ground fault current interrupter (GFCI) outlet or circuit breaker. Other source of heat can be used, but even very small gas or oil heaters will usually overheat a greenhouse this small and may not burn well if not properly ventilated.

The greenhouse will satisfactorily support up to 4 inches of dry snow. If the snow is deeper or unusually wet, one or more temporary supports should be provided along the mid-rib to prevent collapse. If a larger greenhouse is required, the length may be increased. Do not increase the width of the house without increasing the size of the ribs. Doing so will seriously reduce the ability of the house to withstand snow and wind loads.