Photo by Patrick Carey of hadj design

By Ebony L. McCline

Chicagoans trying to make their living space more green could start at the top by transforming an ordinary roof into a "green roof."

In its simplest form, a green roof or rooftop garden is a vegetated roof cover with growing plants and engineered soil that replaces gravel, tiles or bare membrane.

Businesses and commercial buildings have caught on to this phenomenon, and among them are Chicago's City Hall, a Chicago Target store and the Apple Store on Michigan Avenue. However, homeowners are not far behind, says Jim Lindell, national marketing manager for Green Grid, a Vernon Hills-based company that develops ready-made green roofing systems.

Although Green Grid offers pre-planted systems that are planted at their nursery and installed by the company, the do-it-yourself kits are more cost effective for the common homeowner because it cuts the labor costs, Lindell says. The kits are about $10 to $11 per square foot, while the pre-planted systems cost $16-$18, he adds.

"We do get a lot of homeowners saying they want to do this," Lindell says.

Green Grid has offered its modular system services to people who live in condos, single-family homes and 3-flat buildings, he says.

There are two main types of green roofs, intensive and extensive. Semi-intensive, which is sort of a middle ground, is the third type.

An intensive green roof is more park-like. It's the most expensive of the three options and it requires the most maintenance due to its multilayered construction. It could encompass large trees, shrubs and a complicated irrigation system, which makes it less feasible for the common homeowner, says Linda Velazquez, publisher/ editor of Georgia-based greenroofs.com.

The second type of green roof, extensive, is more practical for most homeowners. It's less expensive and has fewer layers. It also requires minimal maintenance, which makes it self-sustainable.

"Most homeowners may benefit from an extensive green roof, but it definitely depends on the weight and the slope of the roof," Velazquez says.

Semi-intensive green roofs have characteristics of both.

One of the most important benefits of a green roof is the energy saving capabilities, says Green Grid's Lindell.

With a regular roof, especially the blacktops, heat accumulates and is absorbed by the building. However, a green roof reflects the heat from the sun, he says. In addition, homeowners are still able to access the roof underneath when using a green grid roof in case there is need for repairs.

Other benefits include: sound insulation, heat insulation during the winter, extended roof life and storm water management, says Larry Merrit, spokesperson for Chicago's Department of the Environment.

There are various things that homeowners need to keep in mind when considering the transition to a green roof, but experts agree that the most important aspect is the hiring of a structural engineer. Communicating with an engineer will help determine if your home is equipped to hold the weight of a green roof, and assess the slope of it and its structural capacity, Velazquez says.

It may be wise to do research before implementing a plan. The Chicago Center for Green Technology, Earth Pledge and www.greenroofs.com, which holds forums on the topic, are good places to start.

In addition, click here for a resource list of local and national businesses involved in green roofs.