All ¡°green¡± roofs are rooftop gardens but not all rooftop gardens are green roofs.

Unlike what one may think of when they envision traditional rooftop gardens, green roofs, or live roofs, are an actual layer of vegetation on a structure¡¯s roof.

According to the United States Environmental Protection Agency, green roofs ¡°can be as simple as a two-inch covering of hardy groundcover, or as complex as a fully accessible park complete with trees.¡±

Though green roofs are hardly recognized as often as other sustainable initiatives, the trend is growing at an incredibly rapid pace.

In 2008, the EPA reported that the U.S. had 8.5 million square feet of green roofing installed or in progress.

The popularity of the projects has grown so tremendously, however, that today there are well over 17 million square feet of green roof and green wall projects in the U.S., according to the International Greenroof and Greenwall Projects Database.

Globally, green roofs account for over 33 million square feet of rooftop.

Some cities have even begun requiring all new construction to have green roofs, with Toronto being the first North American city to do so.

¡°Other than the improved aesthetics of a roof, there are many environmental and economic benefits to green roofs as well,¡± Megan Meier, founder and owner of Higher Ground Green Roofs in Columbus, told The Daily Reporter. ¡°It¡¯s stormwater management, improved air quality, mitigating heat gain and saving energy in the warmer months and extending the life of your roof membrane.¡±

According to the EPA, green roofs absorb heat and act as insulators for buildings, reducing the energy needed to heat and cool the structure.

For example, on hot summer days, a conventional rooftop surface can warm up to 90 degrees Fahrenheit above the surrounding air.

Green roofs, on the other hand, are capable of maintaining a temperature at or below the surrounding air, depending on the amount of vegetation and shade.

And, according to a video produced by the city of Columbus, every three inches of rooftop growth can reduce noise inside the building by up to 10 decibels.

Companies like Higher Ground tout the proven benefits of green roofs for the environment along with the cost effectiveness of the projects.

Aside from reducing energy costs, green roofs provide building owners and developers with Columbus Green Infrastructure Credit, which lowers stormwater service fees for activities that reduce the impact of stormwater runoff and reduce the city¡¯s cost of providing stormwater management.

Buildings that install green roofs can also gain Leadership in Energy and Environmental Design, or LEED, certification credits, which reduce operating costs and qualify builders for tax incentives.

But Meier warned that, while green roofs are typically designed to be low maintenance, they are not entirely maintenance free.

¡°We¡¯ve adopted several green roofs that are two to three years old in need of major weed remediation and plant replacement because there was no maintenance plan in place during establishment,¡± Meier said. ¡°If you start out with the right plants and regular maintenance up front, you can expect a lower maintenance schedule throughout the life of the garden.¡±

In Ohio, almost 400,000 square feet of green roofing have been installed and Meier said that the response to her business specifically has been ¡°unbelievably receptive,¡± though she is a relative newcomer to the game.

One of Meier¡¯s favorite projects is the Chadwick Arboretum at The Ohio State University. There, Higher Ground installed a 12,000 square-foot green roof in the fall of 2013.

¡°This project is so unique because it is publicly accessible, making it a demonstration site for green roof technology,¡± she said. ¡°Most green roofs in Columbus are inaccessible and not visible to tenants.¡±

OSU also has a green roof on Howlett Hall and the City of Columbus installed a one-third acre green roof on top of the iconic Lazarus Building as part of the historic building¡¯s revitalization and LEED Gold certification. Visitors can visit the rooftop space on the Lazarus building, which has a walkway through the vegetation.

Meier said that Columbus¡¯ quick embrace of green roofs is a sign of a bigger trend going on in the city. When asked if she sees a bright future for sustainable businesses in the city, Meier replied, ¡°Put on your sunglasses!¡±

¡°Columbus is embracing sustainability from many fronts,¡± she said. ¡°Green infrastructure, local merchants and farmers, walkable communities, cycling and alternative transportation - it¡¯s a great time to be in this city and I only see it growing from here.¡±

Original:CWA