Up on Roofs? Gardens Help in Several Ways

Green roofs are gaining popularity among owners of residential and commercial properties. Also known as eco-roofs, garden roofs, living roofs, or vegetated roofs, they use plants to absorb pollutants and storm-water. Other benefits of green roofs include cooler interior temperatures during the summer months and warmer interior temperatures in the winter, which effectively reduces heating and cooling costs.

"Extensive" garden roofs employ drought-tolerant plans and require little or no maintenance; but some homeowners are opting for "intensive" versions that need watering, fertilizing, and mowing. Once built only on flat roofs, green roofs can now be installed on slopes of up to 26.5 degrees. They involve several layers, built on top of the roof deck, rigid foam insulation, a waterproof membrane, a drainage layer, and the necessary soil and compost.

Home and business owners in Oregon, Washington, Illinois, New York, California, and Maryland have access to incentive programs that offset the upfront costs, which range from $10 to $20 per square foot.