To provide a house for a hothouse or a relatively low-temp. hothouse that can cultivate plants in all seasons, by providing means for snow load processing, ventilation, lighting and power generation, by reinforcing the structure of the house provided with a foamed resin plate with excellent heat retaining and heat insulating efficiency.

A fixing pipe 1, a center pipe 2 and a slant pipe 3 are provided at interval and provided in the pipes of the house so as to reinforce the structure. Then, a perforated pipe 8 is provided in a flow-in pipe 7 or a flow-out pipe 10. An interval is provided in the perforated pipe 8 arranged in the flow-out pipe 10 so as to provide an air bleeding erected pipe. Solid-state lens configuration 11 using a single lens is provided in lighting. Lens configuration 11 using a solid lens constituted by the combination of objects is provided in lighting. A solar battery 12 (an amorphous-silicon solar battery) is provided in the foamed resin plate.