General Growth Properties (GGP) submitted a plan to

General Growth Properties (GGP) submitted a plan to Howard County, Maryland, officials Oct. 1 that calls for building 5,500 townhouses and apartments and 1 million square feet of retail space during the next three decades in and around Columbia Town Center. GGP, which acquired the Columbia property from the Rouse Company in 2004, would like to start construction in 2010 but recognizes that national economic problems could slow the timetable, The Washington Post reported. The Town Center, key elements of which include an enclosed mall and a concert pavilion, would become a livelier, more intense place with streets that would be more attractive for walking, according to GGP. “We’ve primarily been a bedroom community all these years, and now we would have a real downtown,” said Tom O’Connor, chairman of the Columbia Association board, which oversees much of the community’s public land. The Post said the downtown would be divided into five new neighborhoods. Tree-lined streets, housing above retail, and a sizable complement of affordable housing are included in the proposal, which may take a year to go through reviews, hearings, and zoning changes. Columbia, a 1960s “New Town” between Washington and Baltimore, is home to about 100,000 people.