Our clients, a young couple with two young children, purchased a two-family rental in Cambridge and wanted to turn it into a single family home. The aesthetic mandate was to be clean, bright, light and modern.  Functionally, the biggest challenge were the winder stairs, which were steep and had a very low head clearance, so the first order of business was to figure out where and how a single stair could be introduced.  After many studies, we elected to leave the stair in its current location, but expand a dormer on the top floor to make the stair work. Now, the ribbon stair with custom brackets and railing unify the house, from family living spaces on the ground level to the bedrooms and office/yoga on the top floor.  The detailing is crisp and simple; a European door system that provides full heights doors to the ceiling and an integrated base set the tone for the crisp details elsewhere.  The biggest changes to the interior are on the ground level, where several small rooms were opened up to create a floor through space with a family/living room, kitchen, and dining areas.  At the back, the house extends into the landscape with large double lift and slide doors to the terrace and yard.  Inside, details and materials are simple. Oak floors in a herringbone provide some visual complexity, while the cabinets are detailed with no visible pulls. The cabinet design looks deceptively simple, but the detailing doesn’t allow for hinged doors so all storage is in drawers.  Rift oak cabinets and a simple palate of gray and white set a calm foundation for family life.  On the first floor, massive doors open to the yard beyond, expanding the house both visually and functionally.