Welcome to 3644 New Hampshire Avenue NW, a grand four-level home offering the perfect balance of timeless design, modern functionality, and built-in income. Ideally positioned along one of DC's desirable tree-lined avenues just one block to Petworth Metro Station, this stately residence showcases generous proportions and elegant living areas. A welcoming front porch invites you into gracious, traditional living and dining rooms featuring tall ceilings, warm hardwood floors, and abundant natural light. The updated kitchen boasts ample cabinetry, stone countertops, and stainless-steel appliances, while a convenient powder room enhances functionality on the main level. At the rear, a sunroom opens onto a private deck, perfect for relaxing or entertaining. The second level offers three generously sized bedrooms serviced by a spacious full bath with a soaking tub and double vanity. The rear bedroom provides direct access to a private balcony with treetop views, ideal for morning coffee or evening sunsets. The bonus top floor is a remarkable, versatile retreat, ideal as a primary suite, guest suite, or additional living area, featuring a gas fireplace, wet bar, mounted TV, ample closet space and a full bathroom complete with a classic clawfoot tub. The fully finished lower level serves as an exceptional accessory dwelling unit (ADU) or in-law suite, complete with its own HVAC system, private front and rear entrances, incredible full kitchen, living and dining areas, spacious bedroom, and full bath. This level is currently rented for $1,700/month, with the tenant and lease conveying at settlement - a fantastic opportunity for immediate supplemental income. Outdoors, enjoy a charming fenced front yard and a deep, private rear yard with a privacy fence and secure gated parking for multiple vehicles. From its stately curb appeal to its thoughtfully designed interiors, this home offers unparalleled space, versatility, and investment potentialall just moments from Metro, shops, restaurants, and the vibrant heart of the city.