A green roof is a really good edition to add to your house, your garden, your shed, or in this instance a compost heap. They're a valuable edition to your garden, because they increase the green space for your garden, so it increases habitat value, they also regulate the temperature within the building that they're covering. Green roofs come in all different shapes and sizes, but the basic principle is to create a tray with a mutual of series of different layers which absorb water as well as you're sustaining your soil you put your planting medium in. You can plant different types of plants such as a small meadow, or succulent such as seedings, but the basic principal of the plants are those that are going to take dry conditions as well as wet. And are the basic principals and advantages to having a green roof.