Green roofs and density are two peas in a pod, says the Lancaster County Planning Commission. But while the latter term evokes the sound of grinding concrete, the other chirps with a colorful breeze for the city's smoldering black rooftops.

By planting rows of sedums and perennials on their roofs, seven Lancaster County businesses hope to conserve energy, decrease storm-water runoff and splash a quilt of green covers across the cityscape.

For this, the companies turned to the planning commission, which has been toying with the idea of roof greening for years.

Today, the planners got the county commissioners' OK to apply for half a million dollars in state funds to help them green the rooftops.

Green roofs have been a staple in Europe for decades, and more recently have crept across major U.S. such as Chicago, Atlanta and New York.

The green roof is not a cymbal crash cut in energy use, warned Mary Gattis Schell, a senior planner with the county. Nor is it a miracle cure for storm-water management.

"But collectively, it makes sense," she said.

Gattis Schell estimates that between the seven buildings readying to lay their green up high, there will be an annual energy savings of 181,000 kilowatt hours. That's a 20-percent savings over current energy use, she guessed.

Such installations can also capture up to 90 percent of the rain from storms, Gattis Schell figured.

With the county's currently overloaded water-processing system, some runoff makes its way into streams and rivers without going through the purification process, she said. It takes with it car fuel and other pollutants swept up along the way.

The greening, which Gattis Schell estimates will cost from $10 to $14 per square foot, can bring some relief to the huffing air conditioners in the summer.

Roof air conditioners are the cheapest and most space-efficient units on the market, Gattis Schell said. They pepper the roofs in downtown Lancaster, where a separate construction for the heating and cooling system would be an impossible squeeze. With a green roof, Gattis Schell said, the system will take in much cooler air from the plants, which means it will have to work far less to cool the air being sent inside the building.

Green roofs will also help cool the city, the planners predict, and breathe fresh air into the smog.

Ultimately, "dollars will drive this," County Commissioner Chairman Dick Shellenberger said Tuesday. "If you can cut your air-conditioning costs," the idea will entice others, he said.

Of the seven projects included in the grant proposal, six are inside the city. They are Two Dudes Painting, Box Company Flats, RNL LLC, Penn Stone, the Bare Building and the YMCA. The seventh site is the Columbia Borough Municipal Building.

Collectively, the feature 79,000 square feet of soon-to-be-colorful roof space. The planning commission hopes to cover between 40 and 60 percent of the cost of materials and installation, if the funds come through.

While there are currently no roofers in Lancaster County trained to do greening, the Career and Technology Center will begin teaching roof greening to its students, with the help of the planning commission.

Once the first batch of projects is completed, the roofs will serve as a guide to others interested in greening flat roofs.

The grant application for the state Department of Environmental Protection Energy Harvest Grant is due June 15, with the award announcement to follow in the fall.

CONTACT US: alitvak@LNPnews.com or 481-6020