Scott McAdam, president of McAdam Landscape, said there is a burgeoning appeal of green roofs. A green roof system is comprised of low-maintenance, drought resistant plants that are placed on pre-existing roofs.

The benefits of a green roof system include a reduction in heating and cooling costs, improved air quality, water filtration, extended roof life, long-term economic savings, and aesthetics, according to McAdam.

McAdam Landscape uses the LiveRoof system for their green roof installations. Plants, notably sedum - a small, ground cover plant - are grown in small trays so that the vegetation is fully mature upon installation.

"The green wave is here, and it's here to stay," McAdam said of environmental awareness. "We have done enough to this planet, and we need to rethink some things regarding the environment. Green roofs are a great way to do that."

McAdam Landscape has installed three residential green roofs in Chicago. With a fourth city project already in progress, McAdam said he expects the relatively new trend to continue. McAdam has yet to install any green roofs in Forest Park or the western suburbs.

"Green roofs are a new phenomenon for people," he said. "I see green roofs starting to align very heavily with the commercial market over the next five years. Unfortunately, the residential market might take 10 years."

Newer construction fits well with green roofs whereas some older homes might have too steep a pitch to their roofs.

Opened in 1979, McAdam Landscape continues to adopt environmentally-conscious practices. In 2002, the company installed a porous parking lot at its Forest Park location to filter and capture rainwater before it runs into sewers. McAdam also recycles its topsoil and compost, consequently reducing landfill costs.

A certified installer of LiveRoof since 2007, McAdam has implemented green roofs as merely the latest manifestation of their "cradle-to-cradle" approach.

"Cradle-to-cradle is using a product for its duration and then some," McAdam said. "For example, if plastic milk jugs are turned into a plastic park bench, that's recycling, which is great. But what if there is a better way to use the same plastic over and over. That's a cradle-to-cradle approach.

"The longer I have been in this industry, the more I truly realize what an impact we can have on our environment."

Green roofs have been popular in Europe since the 1960s. Fifty years later, the roofing alternative is finally taking hold in the United States - particularly Chicago.

Chicago Mayor Richard Daley launched a grant program to award residential and small commercial building owners up to $5,000 for planning and installing a green roof. Within a year of that 2005 initiative, more than 250 public and private green roofs spanning some 1 million square-feet were either under design or construction in the city.

"A couple of years ago, zoning was revamped in the counties and that's when green roofs really started to take off," said McAdam Construction Manager Tim Dutton. "New grant incentives were made stronger in the city for private residences."

Dutton cited several housing projects in the city, including one along the Gold Coast, which is promoting an eco-friendly structure as a viable sales tool to prospective residents.

In 2001, a rooftop garden was installed on Chicago's City Hall. Its primary purpose is to provide a green roof demonstration that encourages research and educational outreach at an urban location with a Midwestern climate.

Closer to home, Forest Park resident and owner of Green Home Experts, Maria Onesto Moran, collaborated with EcoGardens to install a green roof on top of Nazareth Academy in LaGrange last spring.

The 720-foot structure, which can be viewed from the school's library and hallways, is filled with native plant species designed to benefit the environment.

"Nazareth Academy is sponsored by the Sisters of St. Joseph who wanted to have a green element to the new construction," said Onesto Moran, a Nazareth Academy alumna. "Green roofs are known as excellent insulators. Depending on the structure, they also are a great way to manage storm water run off."