Green houses are structures built to provide a controlled environment for plants as they grow. Control is provide over rain or amount of water going in and out, weather conditions, diseases and pests
Green house structures are usually built of a metal frame supporting a transparent material to allow controlled environment from the elements.
The environment is kept controlled by use of a cover which is transparent. Traditionally the transparent material was glass, which brings about the alternative name , glass houses, but may be plastic polythene sheets or perspex.
The Structure framework may also be made of other material e.g plastic pipes or more usually, wood.
The determining factors for the structure are initial cost and cost of maintenance,