Roof greening effect diagram of a building

Quick answer：

Roof greening refers to the practice of planting vegetation on the rooftops of buildings. This can include various plants, such as grass, herbs, and small trees, which are grown in specially designed planters or in the soil itself. The benefits of roof greening include improved air quality, reduced urban heat island effect, and energy savings due to insulation. An 'effect diagram' would be a visual representation showing how a roof greening project will look once completed.