Green roofing is cost efficient and attractive. Using a green roofing system can give extra insulation that helps keep energy consumption down. It can be used on some parts of the roof or for the entire roof. If you will not use green grass roofs, you can still go green by controlling storm water runoff with perimeter drains, gutters and subsurface drainage systems. You can collect rain water using rainwater catchment so that it can be used for washing clothes, flushing toilets, watering plants and irrigating landscapes. Do not use asphalt shingles if you plan to use rainwater for vegetation and drinking.