As the summer heats up and the rain continues to pour down, you may be thinking about how to cool your house and reduce rainwater runoff. Green roofs (also called living roofs) are a great option to help keep pollutants out of the city’s drain system and reduce flooding. Typical green roofs, which usually consist of provide a number of environmental and financial benefits retain 70 – 90% of precipitation and allow the water to distribute slowly through some runoff, evaporation, and transpiration through the plants. They protect your underlying roof from weather and sunlight, making it last longer and allow less heat into your home.
“Extensive” green roofs (as opposed to “intensive”) allow for up to 6 inches of plant growth, utilizing hardy, drought-tolerant grasses and succulents that require very little maintenance once installed. Extensive green roofs can be installed on almost any roof, including small roofs over garages or sheds and sloped roofs. The only installation requirement is adequate reinforcement of the underlying roof. A typical extensive green roof weighs 30 pounds per square foot when saturated with water. According to Green Roofs for Healthy Cities’ 2013 Annual Green Roof Industry Survey, Baltimore City ranked in the top 10 U.S. cities for green roof square footage. The city’s most famous green roofs can be found atop the National Aquarium in Baltimore, the Maryland Science Center, and the city’s only non-profit retirement community, Roland Park Place. Although the city does not provide any financial incentive to install green roofs, Blue Water Baltimore’s Water Audit Program can provide a free assessment of your home and determine whether a green roof if possible and affordable. As long as your green roof project conforms to its requirements, the Water Audit Program also offers rebates on the total cost of your project. Blue Water Baltimore has created a list of contractors in the Baltimore area with experience creating extensive green roofs on residential buildings.
Installing a green roof on your home typically costs between $15 and $30 per square foot, although the cost can be higher is your roof requires reinforcement. In Baltimore City, you are required to obtain a construction permit before installing a green roof. This can be done at the One Stop Permit Center at 417 E. Fayette Street, Room 100. There is a one-time, non-refundable application fee of $25.00 in addition to the permit fee. Generally, the permit fee will be charged at a rate of $10.00 per $1,000.00 of estimated costs for the project.
NOTE: If you live in a Commission for Historical and Architectural Preservation (CHAP) district, any exterior modifications to your residence must be approved by CHAP. Your permit application at Baltimore Housing will be forwarded to CHAP, from whom you must obtain a Notice to Proceed.