Living Roof technology

Contrary to some popular beliefs, green - or living roofs are not too heavy or expensive. An engineer can design a roof structure for nearly any environment. There is not as much weight for these as most think as various technologies to implement these roofs have come a long way. The average extensive (thin commercial) living roof is 18-24 pounds per square foot fully saturated, well below the live weight loads of most American roofs. The price ranges from six to fifteen dollars per foot installed depending on access to the roof.

A living roof can double or triple the life of the roof membrane. The cost of a roof membrane is approximately seventeen dollars a foot so clearly the living roof pays for itself in extending the life of the membrane itself. Then there are the energy savings. As much as 25% on heating and cooling on a two story building. With the cost of heating bills continually rising this can become a major addition to a cost cutting opportunity to your building.

In the NY area we found a company, Greener Designs that built the living roof at Silvercup Studios in NYC (30,000 square feet) and they are reporting noticeable heating and cooling savings two years later.

Living roofs up to approx. 45º are a normal occurrence in countries like Spain. They use a plant called ’sedum’ not growing more than 8 centimeter high in trays 60X60 cms with an intelligent micro-irrigation system. That area receives approx. four to six months of beautiful white or pink flowers in the roof. No problem with humidity due to a special treatment of surface and maximum isolation. Living roofs in areas around 30º are perfect to integrate efficient and visually solar panels. Thermic diode solar panels don't produce electricity and photovoltaic are a 12 V. system. In general there is no specific problem to date with electrical fittings open air.

Living roofing is a wonderful scenario and something that we are working with in some of our development projects we have in TX and CA. We are integrating living roof ideas to add livable square foot usage to footprint homes that can then utilize some other optional areas since the lot sizes are minimal. These rooftop gardens offer the homeowner the land use they deserve and pay so much for. Also, we are using living roof designs to offset leach field space necessary for septic systems in outlying areas on small lot projects. Using the rooftop to help with an aerobic septic system we have been able to control the waste water and return it to grey water to be used for the plant irrigation watering systems on the property.

There are numerous and creative ways and usage designs that are coming out today. We should all think more strategically and ecologically in our future developments and renovations to create ways to give back and maintain our water, material, utility, and mineral usage of our planet.