Rarely available in Harvard Square, this brand-new ground-up single-family home combines elegance and sustainability with solar panels, energy-efficient HVAC, and EV charging. The open-concept first floor offers a chef's kitchen, dining area, and a living room with a gas fireplace. Upstairs, a vaulted-ceiling primary suite features skylights, a walk-in closet, and a spa-like bath. 2 additional bedrooms, laundry, and ample storage complete the level. The lower level provides a versatile bonus room, bedroom, and full bath. Enjoy a private patio and 3 off-street parking spaces--all steps from the best of Harvard Square! This freestanding single-family home is part of a two-unit condo association with 57 Museum St. Buyers have the option to purchase both 55 & 57 Museum together--ideal for extended family!