BALTIMORE (Map, News) - The Hilton Baltimore Convention Center Hotel is taking green building to another level — the roof level.

The $301 million, 750-room hotel next to the Baltimore Convention Center will include the Baltimore area’s largest green roof when construction is completed in August. The 32,000-square-foot green roof is located on the hotel’s east and west buildings.

Dan Freed, principal of RTKL Associates, the architectural firm with offices in Baltimore that designed the hotel, said he didn’t know of another hotel in Maryland with a green roof the size of the Hilton’s.

“Hotels are a little behind the curb on sustainable issues,” Freed said. “We’re already seeing more hotels catch on to the trend.”

RTKL began designing the hotel in 2002, and Baltimore City, which owns the property, wanted a green roof incorporated in the plans from the beginning, Freed said.

“You can’t force a private developer to do a green building,” Freed said. “The city’s making an effort to do more green building.”

Installation of the green roofs began in early November on the east building and included 60,000 1-inch plugs of six species of plants. The second roof should be completed in three to four weeks.

The Furbish Co., a Baltimore-based firm that specializes in sustainable building systems, installed the hotel’s green roofs. The installation cost about $12 per square foot, said Michael Furbish, president of The Furbish Co. Furbish said the roof would help with storm-water management. The roof controls erosion and runoff because 65 percent of rainfall will remain on the roof, nourishing the plants. Living roofs help keep buildings cooler, thus reducing HVAC cooling loads and lowering utility bills.

The plants also provide significant protection against ultraviolet damage and minimize expansion and contraction of the roof caused by temperature variations, which can cause structural damage. “You would usually have a 15- to 20-year warranty on the waterproof membrane on a roof,” Furbish said. “With a green roof, you have a membrane that could very well last 80 years, which is an economic benefit for building owners.”

Furbish said the green life on the roof is self-sustaining and will require little maintenance, other than periodic weeding and trimming.

acannarsa@baltimoreexaminer.com