Benefits of a Green Roof
Types of construction today are very different than 50 years ago. Today “green” construction and the use of sustainable and environmentally friendly materials are becoming more standard and desirable.
Green Roofs, Vegetated Roofs or Living Roofs are one type of “green” construction. Green roofs can be installed on existing or new buildings. Existing building installation may be more difficult due to existing roof load limitations, roof slopes and roofing materials. New building installations are less complicated but still require careful consideration.
Green roofs work through the installation of soils and specific plant species on a roof. The soils and plants absorb and filter pollutants from water that would traditionally sheet flow across pavement collecting pollutants such as gas, oil and sediment and transporting it directly into storm sewer systems or creeks and rivers.
Green Roofs Provide:
- Improvements in the quality of storm water runoff
- Improvements in air quality
- Increases in land use efficiency
- Increases in energy efficiency
- Natural cooling system for buildings
Plants species on green roofs provide an added layer of air filtration that can reduce dust and smog pollution. Plant photosynthesis also assists in the reduction of greenhouse gases.
Capturing storm water on the roof reduces the impervious surface on a site resulting in a more efficient use of land and more buildable area, which translates to more leasable space. Green roofs can also provide habitable space for users of the building.
Green roofs provide a natural cooling system for buildings. Typically a roof generates heat because of the materials direct exposure to the sun. Adding vegetation to the roof cools the roof, assists in insulating the building, reduces energy demands minimizing urban heat island effect, which decreases annual heating and cooling costs.
Before you decide whether a green or vegetated roof is right for your building additional information should be gathered based on specific criteria, including geographic location, building location, climate and maintenance capabilities. You may also want to consider if the green roof will reduce your impact on the environment and what your initial investment versus return on investment will be. Green roofs are typically more expensive than traditional roofs and can be installed for $10-24 per square foot, but can last twice as long, and require less maintenance.
Green roofs are growing in the commercial industry. Ford Motor Company, Ann Arbor District Library Malletts Creek Branch, and Ann Arbor City Hall are a few examples of buildings with green roofs. For more information and benefits on green roofs check out Michigan State University’s research.