COPT Defense Properties (NYSE: CDP) ("COPT Defense" or the "Company") announced the acquisition of Stonegate I, a 142,000 square foot Class A office building at 15050 Conference Center Drive in Chantilly, VA for a gross purchase price of $40.2 million. The Class A office building is fully occupied by a top 20 U.S. Defense Contractor with 10 years of lease term remaining, making this their ninth location in the Company's portfolio. Stonegate I was constructed in 2000 and is within a 1-mile radius of the Company's 1.5 million square foot Westfields office portfolio, which is 94% leased.