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There are several purposes of a living roof, especially for urban areas. They help keep the water off roofs and avoid damage to roofs by absorbing rainwater. Living roofs significantly increase the life span of a roof, saving the owners of the building thousands of dollars in maintenance and replacement costs. In addition, living roofs can also help reduce the temperatures in urban areas and provide insulation, reducing costs for heating and cooling the building.
Categories of Living Roofs
There are three types of living roofs: intensive, semi-intensive and extensive. The main difference between the three is the planting depth of the vegetation and the amount of maintenance they require. An intensive living roof can support between 80 to 150 pounds of vegetation per square foot, whereas an extensive living roof supports between 10 to 25 pounds of vegetation per square foot.
An intensive living roof, which could be a lawn or vegetable garden, requires more up-keep than an extensive living roof, which is designed to be more self-sustaining. While intensive living roofs may be enjoyed by many of the building's residents, extensive living roofs are usually restricted due to the need for high maintenance.
Homes with sod roofs, which are seen in many countries, provide insulation for the home, helping to keep it warmer in the winter and cooler in the summer. Other homes or smaller buildings have used their roofs to plant exotic grasses and plants, providing benefits for the owner of the property and giving passersby something visually appeal to appreciate.
Living roofs are a relatively new concept, but city governments have quickly caught on to their advantages and now provide tax incentives to businesses for building living roofs. They help filter rainwater as it falls and attracts beneficial insects, bees and butterflies back into the cities, renewing the environmental landscape of many large cities and providing an oasis to relax in for people.