Green Roofs: Reducing Energy Use and Elevating Quality of Life
If you take a moment to stop and look around your town or city more closely, specifically the roofs of buildings, you may start to notice an emerging trend in one of the most unlikely places. Green roofs, or rooftop gardens, are popping up all over the place on top of commercial, academic, and residential buildings and facilities. They range from a simple two–inch covering of groundcover or a complex, accessible park. And while they are aesthetically pleasing and can brighten up any industrial area or concrete jungle with a hint of green, they can also provide numerous environmental and energy benefits to the building, as well as the surrounding area.
Although initial costs to install and upkeep a green roof are higher than those of conventional roofing materials, the return on investment can be significant due to a green roof’s effect on reduced energy use and consumption. A green roof creates shade and absorbs heat when wet, making the surface temperature of a roof lower on warmer days. This reduces the amount of heat transmitted into the building, and avoids the need for a building’s HVAC system to work harder to keep a room cool or comfortable by alleviating temperature fluctuations.
This heat-trapping affect is especially beneficial for those up here in the Northeast. Dry, green roof layers can act as an insulator in the winter months, decreasing the flow of heat emitted through the roof, therefore reducing the energy needed by a buildings control systems to stabilize the interior temperature. That can translate into lower heating costs and energy consumption.
Costs to implement green roofs can also be mitigated through better storm water management practices. Just like when you water a house plant or your front lawn, the vegetation on a green roof absorbs rain fall and can reduce and slow a building’s storm water runoff. This process not only helps the surrounding environment by filtering pollutants, but also can cool a building’s interior, again reducing energy use of a building’s heating and cooling system and saving customers money.
One of the most notable green roofs that come to mind in the area is the Macallen Condominiums in South Boston. As the first residential building in the City of Boston to earn a LEED Gold rating, the wedge-shaped building has a sloping green roof thrives with its orientation toward the sun, and the angle allows for gravity to force rainwater down to tanks for recycling and irrigation. All told, the building uses 600,000 less gallons of water annually and uses 30 percent less energy than traditionally constructed buildings.
In addition to reducing air pollution and greenhouse gas emissions, improving the quality of life for occupants and surrounding areas, green roofs can have a significant positive impact on buildings’ control and HVAC systems that allows for reduced energy consumption and a stronger bottom line.