What amount of energy savings can be realized with the implementation of a Green Roof System?
It is very difficult to give a specific answer to this question because of the many different variables involved in the design of a roofing system. Typically, the insulation value of a roof will not be influenced by the use of a green roof system. As an example, if the energy code requirement for a roof system is R-20, that R value should be obtained by the use of rigid insulation similar to any other industrial commercial roofing system. Additional energy savings will be realized from the basic cooling effect of the green roof covering and the evaporative effect of retained moisture. The depth of the soil will provide some R value, but when it is saturated it cannot be calculated into an R value. The green roof itself by nature will absorb energy rather than reflect it due to the organic matter, color and openness of the plant medium. The cost to run mechanical equipment installed on the roof will be somewhat decreased due to the lower ambient temperature of the surface of a green roo
