Green roofs are the new shingles. For many people looking to reduce their carbon footprint and up the ante from simply recycling, roofing is the new frontier and the latest source of alternative energy. Broadly defined, green roofs are environmentally friendly roofs, generally composed of either solar panels (sometimes called cool roofs) or, more commonly, indicating a roof where shingles and tar have been swapped out for soil and gardens.
The garden variety green roof contains a mix of soil and vegetation carefully separated from the rest of the building by a waterproof membrane that acts as a more natural insulation device, collecting rainwater and helping to regulate heat-island effects and temperature in urban areas. Of this variety two types exist: intensive and extensive. The separation of the two is defined by the thickness of the soil, and thereby, the level of variety a roof can support. Intensive roofs have a larger depth and are ideal for plants whose roots need more room to grow and thrive. The downside to intensive roofing, as the name suggests, is that these roofs require much more upkeep and add considerably more weight to the buildings structure. Thus, intensive roofs are generally the more expensive option. Conversely, extensive roofs have a thinner layer of soil and support horticulture of grass, flowers and shallow-rooted plants such as stonecrop, onion, desert sage or prickly pear.
Liveroof.com suggests that green roofs can generate an energy savings of up to 25 percent and can potentially extend the lifetime of the roof from 100 to 200 percent. The rise of green roofs in many urban areas, such as the rooftop of Chicago’s City Hall, signals the beginning stages of a future where cities can produce their own sustainable levels of produce and significantly lower their energy needs. This vertical farming will lead to job creation and enhance the farming industry, thereby enhancing the communities in which they exist. This will also mean that phrases such as “farm fresh” and “locally grown” can be appropriately applied to major cities and urban areas.
Residentially, green roofing is still a little ways off from commonplace utilization. The reasons are varied. The initial costs of green roofs are higher than conventional roofing techniques but, in the long run, average out to about the same costs. The weight burden, especially with intensive roofs, can generate extra stress on the structure of the building and sometimes requires additional construction to handle this added weight.
The other version of green roofs, those fitted with solar panels, is much more popular and much more feasible for the average homeowner. These panels generate electricity through a Photovoltaic process that converts sunlight directly into direct current electricity. With a converter, these homes can transfer the DC electricity into alternating current, the most commonly used form of electricity, and making the house virtually identical to that of one still connected to a city grid. Unlike the previous green roofs, this method of green roofing doesn’t involve a drastic overhaul to a building’s infrastructure; instead, many of these panels are simply mounted directly to the pre-existing roof.
Although green roof technology can be seen as early the 7th Century BC with the Hanging Gardens of Babylon, it is only in the early stages of utilization. While many new developers are turning to green technology, it will still be some time before its proliferation in the residential market is attained.
About the Author
Patrick O’Houlihan writes about interior design accessories, like red sheer curtains. He also has recently made the switch to vegan.