Welcome to 17 Williams Street — a rare opportunity to own a well-built, energy-efficient duplex in a peaceful Lewiston neighborhood. Constructed with insulated concrete forms (ICF), this 3,300 sq ft home offers exceptional durability, quiet living, and year-round comfort. Each level features 3 bedrooms, 2 bathrooms, in-floor heat, mini-split A/C, vaulted ceilings, and an open-concept layout. Both units include private laundry and a smart, functional floor plan, plus a newer roof for added value and peace of mind. Live in one unit and rent the other to cover more than half your mortgage, making ownership surprisingly affordable even with taxes. Ideal for an owner-occupant, multi-generational living, or as a strong investment property — with the flexibility to convert back into a spacious single-family home if desired. Located in a quiet residential area close to schools and amenities, this is a smart buy and a rare find in today’s market.