Brand-new duplex condex-  This Cape-style townhouse condominium shares just one side wall, so it lives like a single-family home. You own your side outright, with your own entrance, garage and private backyard, and none of the upkeep of a big complex.  The home has 1,399 sq ft of finished living space with 3 bedrooms and 2.5 baths. A tuck-under two-car garage opens into a mudroom entry. The main level has an open-concept layout, and the primary suite has a private bath and an 8' x 5' walk-in closet. Granite counters are in the kitchen and baths. It's efficient too, with mini-split heating and cooling, high R-value insulation, electric appliances, and city water and sewer. A mature wooded buffer out back keeps the yard private.  New construction, energy efficiency and classic New England charm, with little to maintain.