Exceptional space, flexibility, and value in one of San Marino’s most desirable north-side neighborhoods. Offering approximately 4,300 sq. ft. of total living space, this extensively remodeled property includes a 3,500 sq. ft. main residence with 4 bedrooms and 4 bathrooms, plus a brand-new 800 sq. ft. detached ADU with 2 bedrooms, 2 bathrooms, a full kitchen, and living room—ideal for extended family, guests, a home office, or independent living. Set on an approximately 12,826 sq. ft. lot, the main home blends classic San Marino character with thoughtful updates. The formal dining room opens to an updated gourmet kitchen with granite countertops, newer Frigidaire appliances, and a bright breakfast room. Three spacious bedroom suites are located on the main level, while the second floor features a private master bedroom suite with retreat/loft. Multiple living areas provide excellent space for entertaining, relaxing, and everyday living. The newly completed ADU is a standout feature, functioning as a truly independent residence and adding exceptional versatility to the property. Outside, redesigned landscaping surrounds the home with mature greenery and flowering plants, while one expansive rear patio are perfect for outdoor dining, barbecues, and entertaining. A fully paid solar system adds energy efficiency and long-term savings. Ideally located in north San Marino near The Huntington Library, Art Museum, and Botanical Gardens, the home is also convenient to local schools, parks, shopping, dining, and other community amenities. With 6 bedrooms, 6 bathrooms, approximately 4,300 sq. ft. of total living space, a new ADU, extensive upgrades, and paid solar, 555 Sierra Madre Blvd offers a rare combination of space, flexibility, and value in San Marino.