The Potomac Yard development will be on its way to gaining another massive chunk of office and retail space when developer Meridian Group breaks ground on its 445,000-square-foot National Gateway building next week.

Meridian is the master developer for a 40-acre plot of Potomac Yard that sits in Arlington. The area encompasses more than 300 acres and straddles Arlington County and the city of Alexandria, both of which began planning to redevelop it about seven years ago.