Burlington, MA – TRB Realty (TRB) founded in 2003, announced that it has completed the sale of a leasehold interest of 21 A Street, Burlington, MA, an attractive 8,000SF+/- single-story office building on a slab, with slightly less than 1 acre of land and approximately 30 parking spaces. TRB Realty was the sole broker of record in the transaction.