A greenhouse 10 includes a base portion 20 and a roof portion 30 supported in operation by the base portion, characterized in that the greenhouse includes at least one of: (a) at least one window 80 in the roof portion； (b) at least one window 90 in the base portion； (c) at least one of the windows is held into position through a clamping system 209 comprising an elongated member 210, 255 and a cover member (230, 250)； and (d) at least substantially 55% of the structural stiffness and strength of the greenhouse is contributed to the mounting of the windows in the greenhouse. The greenhouse is potentially economical to manufacture, easy to assemble, and robust in use. Moreover, the greenhouse is flexible in operation. Multiple such greenhouses can be mutually coupled together to form larger greenhouse assemblies.
