154 West Newton Street, Unit 1 is a rare South End residence that pairs the architectural character of a classic brownstone with exceptional scale, sophistication, and modern functionality. Reimagined through the seamless combination and renovation of two residences, this expansive lower-level triplex offers nearly 2,600 sqft of thoughtfully designed living space, 3 bedrooms, 3.5 bathrooms, 3 private entrances, outdoor space on every level, and direct-access 2-car tandem parking. Extending beyond a typical brownstone footprint, the home features remarkably generous proportions and light-filled interiors on all three levels. Soaring ceilings, curved bay windows, custom millwork and dramatic walls of glass lend architectural distinction throughout. The gracious parlor level features an inviting living room anchored by a gas fireplace and a generous kitchen appointed with a six-burner Wolf range, Sub-Zero refrigeration, abundant cabinetry, and dedicated pantry storage. A defined dining area flows to a striking wall of floor-to-ceiling steel-framed windows and a door opening onto a private deck with gas and water connections, an effortless extension of the home for al fresco dining and entertaining. One level below, the serene and expansive primary suite features floor-to-ceiling windows, a private balcony, custom-fitted walk-in closet, and an ensuite bathroom with radiant-heated floor, and a glass-enclosed shower. A second bedroom and beautifully finished full bathroom with soaking tub complete this level, offering comfortable accommodations for family or guests. The flexible lower level is equally suited to everyday living, working, and entertaining, featuring a third bedroom and full bathroom alongside a spacious family room with custom built-in bookcases, a custom-built office nook, and a fully equipped wet bar with wine refrigerator, dishwasher, and sink. Double glass doors open directly to a private, professionally landscaped and fenced patio, creating another inviting setting for outdoor relaxation and gatherings. Additional features include high-velocity air conditioning, integrated speakers, abundant storage, and two assigned parking spaces. Privately positioned on coveted West Newton Street yet moments from the restaurants, cafés, boutiques, and cultural attractions of the South End and Back Bay, this exceptional home offers an uncommon combination of scale, light, architectural character, refined finishes, outdoor living, and modern convenience.