Courtesy Hacin + Associates

Construction of a long-delayed luxury condo project at 55 India St. in Boston could begin next spring following the Greenway-facing development site’s acquisition this week by Boston Residential Group.

Boston Residential Group plans to develop 29 condos, a majority of them three-bedroom and two-bath units, to fill an underserved niche in the downtown market, CEO Curtis Kemeny said in a statement.

Plans approved in 2014 by the then-Boston Redevelopment Authority call for 44 condos in a 12-story, 67,000-square-foot building on the 7,100-square-foot site, which has been a parking lot since the 1950s and faces the Rose Fitzgerald Kennedy Greenway.

Boston Planning and Development Agency spokeswoman Bonnie McGilpin said the agency has not determined if the new design requires the developer to file a notice of project change.

The purchase price for this week’s transaction was $8.2 million, according to a Suffolk County deed, and the transaction includes another $4.5 million for 30 parking spaces in a nearby garage, a Boston Residential Group spokesman said.

The seller, Boston-based brokerage Otis & Ahearn, bought the property in August 2014 for $1.4 million.

The brick-and-granite exterior building would retain a ground-floor restaurant space, Boston Residential Group said.