A maintenance free greenhouse, fully galvanized and covered with film is very easy and fast to build even with unskilled labour. All components are prefabricated, the modular system can be built in any multiple of the modular sizes. The open top roof allows a continuous air flow to reduce the inside temperature to the optimum level. The open roof has a wide ant-rain overlap, protecting your crop from in flowing in rain. Structure is covers with 200 micron. polyethylene film. The open roof can also be made fully insect proof by fixing an additional screen of insect netting.