Residential Addition & Renovation, Lexington, MA. One of the original homes built in the neighborhood in the 1870s, the 1,300-square-foot, mansard-roofed house had undergone little change for many decades.  The recent owners sought an economical way to add needed living space for their family of 5.  The agenda included replacing the kitchen, adding two bedrooms and a bathroom, and upgrading insulation and mechanical systems -- all within the constraints of a tight budget.  A two-story addition in the rear provided the needed space without changing the house’s presence from the street.  It allowed for an expanded kitchen and dining area, and a new family room and mudroom on the first floor, and for a master bedroom and bath and a fourth bedroom on the second floor.