Own a Piece of Londonderry History! Welcome to 18 Windsor Boulevard, home to the first legally approved Accessory Dwelling Unit (ADU) in town. This exceptional property has undergone extensive recent updates and is ready for its next owners. Major improvements include a new roof, new siding, and a brand-new deck, providing peace of mind for years to come.  The beautifully appointed above ground ADU features hardwood flooring throughout and direct access to the inviting screened porch, making it ideal for multi-generational living, guests, or rental opportunities. The main residence offers three spacious bedrooms, including an impressive primary suite with a loft, walk-in closet, and abundant space to unwind.  Designed for both everyday living and entertaining, the first floor boasts a generously sized family room and a beautifully updated kitchen complete with granite countertops, tile backsplash, double ovens, and a pantry. Step outside to enjoy the screened porch and expansive new deck overlooking the peaceful, fenced-in, wooded backyard.  Offering flexibility, comfort, and room for everyone, this meticulously maintained home is a rare opportunity in one of Londonderry's most desirable locations.