Green space in urban environments is sometimes hard to come by. Many homes in the city have no green space while those that do tend to be very small yards, gardens or patios with potted plants. Fortunately, there are parks and playgrounds hidden away within some neighborhoods. In Richmond, one often has to search to find green space if not immediately adjacent to the James River corridor.

Green space, also known as green infrastructure, competes for real estate with grey infrastructure which is our city's roads, buildings and other 'hard-scaped' developments. Conserving green space is in a fight to mitigate air pollutants, the runoff that goes into our sewers, temperature and even the aesthetic qualities of our city.

Of the many different ways we can add more green to our urban environment, green roofs are an obvious and pleasant strategy. Green roofs are a relatively new idea that has finally caught on in America. They have the potential to make a tremendous difference in the visual landscape and environmental qualities of cities.

A typical green roof has a top layer of vegetation, followed by a growing medium. Below the plants there is a drainage system followed by a layer of insulation, a root barrier, and a waterproof membrane to protect the building's roof itself.

Among their key advantages, green roofs slow storm water runoff so there are less sewer overflow problems; this presents a huge economic savings potential to the city. The uptake of carbon dioxide in the plants and soil helps against the abundance of carbon in the air.

Green roofs are also a solar absorber, reducing what is known as the urban "heat-island" effect. The heat island effect is where city air and surface temperatures are higher than nearby rural areas. This is caused by the impermeable (paved) surfaces of our city. An example would be to consider the city of Richmond as a "heat island", absorbing more heat than cooler rural areas like Caroline, New Kent and Goochland Counties.

There are pros and cons for every green roof system. Depending on how much money you want to spend, a green roof can consist of: 1) a very lightweight, thinly soiled, low maintenance roof with limited plant choice and less insulation; 2) a diverse, attractive garden having good insulation properties but a greater energy need for water and materials.

While the short term costs of green roofs may be higher, they can last twice as long as normal roofs. Plus they shield against UV rays, potentially offsetting higher electric bills by providing shade in the summer and insulation in the winter (as much as 30 percent according to Timothy Beatley, author of Green Urbanism: Learning from European Cities).

Green roofs are already very common in Europe. The city of Linz in Austria started to require building plans to compensate for the loss of green space taken by buildings in the late 1980's. The city subsidized the installation of green roofs and, according to Mr. Beatley, it will pay for 35 percent of the cost!

In the U.S. the green roofing industry is only a few years old. We have at least two green roofs in the Richmond metro area. Richmond's first is the SunTrust building downtown that maintains an 11,800 square foot green roof, installed in 2005. Union Bankshares Corporation's (UBSH) Carmel Church operations center (in Caroline County) was completed in the spring of 2007 with a 23,000 square foot vegetated roof consisting of a variety of plants including sedum (see picture below).

I was able to visit UBSH's green roof in July, 2007. To be honest, it didn't look that 'green', mostly because their sedum plants were very young and hadn't grown much. I revisited last week and found that the plants are growing nicely.

Mr. Olen Thomas, UBSH Director of Marketing, states that the plants are becoming maintenance free without having to water them as often as when they were first installed. The great thing about the sedum plants is that they don't die if it doesn't rain; they just lie dormant and grow quite well with moderate precipitation. That is how these plants survived last year's drought.

Several organizations are contributing to the future of green roofs in the Richmond area, including the Green Roof Task Force (GRTF) which comprises roofing contractors, design professionals, government officials and product manufacturers in the Richmond area. The intention of this assemblage is to have a diverse and cooperating group that represents the entities involved in the green roof industry. 

Mr. Scott Shufflebarger is the chairman of the GRTF. According to Mr. Shufflebarger, "(the nation) is moving slowly in adapting to policy that is more conducive to vegetated roofing." He says that the GRTF is willing to be involved in the development of legislation pertaining to green roofs in Virginia. 

The GRTF met for the first time recently so there are no initiatives proposed as of yet. Mr. Shufflebarger says that "they are trying to act fast; to be ready with something before the next (General Assembly) session begins."

Green roofs are a benefit to the health of urban ecosystems. It's depressing to see all these empty rooftops gathering heat. Why not throw some soil and plants up there that can sequester carbon, lessen runoff and create an attractive viewpoint for others? 

With more viable technology, decreasing installation costs, some financial backing from future legislative incentives, and increased citizen environmental stewardship, it's just a matter of time before green roofs become commonplace in the market.

UBSH’s Green Roof in July 2007 (left) and July 2008 (right).

David Martin is an environmental consultant in Richmond. He has maintained a devoted study in environmental issues since his early teens, when his sister would kidnap him from home and take him to Blacksburg to appreciate Geology, go hiking and tube the New River. David recently fled the country of Ghana because he received too many marriage proposals.