Green Roofing

Green roofs are vegetative plantings that are installed on the roof of a building. Green roof technology is not new. After decades of practice, space-cramped Germans have honed the practice to a fine art. In Berlin, 50% of roofs are green roofs. E&E offers this superior German green roofing system, widely used in Europe.

Although often used on flat roofs, a low and even high pitched roof can be "greened" using our soil stabilizing Green Roof product. The grid is installed and then low growing plants such as grasses and sedums are used where the soil depth is only a couple of inches. Where the medium depth is several feet, shrubs and even small trees can be used.

Advantages of Green Roofing

Reduced Energy Costs

When the outside air temperature reaches 80°F, surface temperatures of traditional black rooftops and concrete surfaces can be as high as 180°F. Rooftop heat loads affect the amount of energy necessary to cool buildings to desired temperatures. Because of their insulating properties, green roofs have consistently and significantly reduced rooftop heat loads in warm seasons, even more so than reflective white roof membranes. Green roofs have been shown to reduce heating and cooling costs from 25% to 50% for the floor directly below the roof. They can also significantly slow a building’s heat gain and loss. As a result, the HVAC systems of buildings equipped with green roofs operate more efficiently, translating in lower energy costs for the building owner and better aesthetics for the tenants.


Reduced Urban "Heat Island" Effect

The urban "heat island" effect occurs in most of the large cities of the world. This phenomenon has been shown to actually change weather patterns in some cities. Dark asphalt roads and building rooftops absorb a significant amount of heat during daylight hours. This heat, in turn, is radiated back into the atmosphere by day and into the night, causing further warming. To compound the problem, additional heat is emitted by vehicles and HVAC systems. These factors can result in a 2 to 10 degree temperature increase especially in large cities. Green roofs help to insulate and shade buildings from the brunt of this heat by reducing the heat signature a road leaves on the environment and occupants of the building.

Sound Insulation

Green roofs serve as excellent sound insulators. Tests have shown that green roofs can reduce the indoor noise pollution from outdoor contributors by as much as 10 decibels. Noise-level reductions can provide significant benefits to buildings in noise-impacted areas, such as sites close to airports, highways, or heavy industry.

Extended Roof Life

Green roofs protect exterior roof membranes from ultraviolet radiation, extreme temperature fluctuations, punctures and other physical damage, thereby greatly increasing the life expectancy of the roof. When the life expectancy of a roof membrane increases, the need for costly roof replacements and maintenance decreases, resulting in tangible savings for building owners.

Aesthetics

Green roofs provide both visually pleasing vistas and functional space through serene rooftop gardens and gathering areas. In addition, green roofs often help increase the values of condominiums, apartment complexes and office buildings. They also help industrial and commercial properties blend into suburban and rural areas.

Storm Water Management

Especially in urban areas, over 75% of a rain event can become surface runoff depositing pollutants into waterways. Green roofs help alleviate this problem through retention of rainfall and detention of roof water runoff. Green roofs can greatly reduce the risk of flooding, sewer overflows and subsequent discharges. Once the green roof is saturated, the water slowly percolates through the growth on the roof, becoming roof runoff. This occurs several hours after peak flows from impervious surfaces have subsided and provides additional time for municipal sewer systems to handle other uncontrolled runoff.

Information provided by Energy& Environment and Columbia University