Nestled on one of Park Slope's most picturesque, treelined blocks, 879 Union Street presents a rare opportunity to own a grand 21 foot wide brownstone that seamlessly blends historic charm with exceptional flexibility and income potential. Built in 1885 and spanning approximately 4,030 square feet, this stately residence is configured as a 5 unit property, offering both an expansive owner's home and strong rental performance in one of Brooklyn's most desirable neighborhoods. For the end user, the garden duplex delivers a true brownstone lifestyle - thoughtfully scaled with 3 bedrooms, 2 baths, and a private deck that opens to a generous landscaped garden. Rich prewar details - including original woodwork, tall windows, hardwood floors, and soaring ceilings - create a warm, inviting atmosphere that is both timeless and livable. The home is further enhanced by private access to the cellar, adding valuable bonus space for storage, recreation, or customization to suit your needs. For the developer or investor, the property offers substantial upside. Configured with 4 free market rental units above the owner's duplex, the building provides immediate income with long term growth potential. Its rare 21' x 48' footprint allows for a range of strategic possibilities - whether optimizing the current rental mix, upgrading finishes, or reimagining the layout to maximize value. In addition, the property benefits from ample unused air rights, presenting a compelling opportunity for expansion and further value creation. The combination of scale, width, and development potential is increasingly difficult to find, making this a uniquely adaptable asset in a supply constrained Park Slope market. Positioned between 7th and 8th Avenues, just moments from Prospect Park, Grand Army Plaza, and some of Brooklyn's best dining, shopping, and transportation, 879 Union Street offers the perfect balance of tranquility and connectivity. Whether envisioned as a luxurious primary residence with rental income, a multigenerational home, or a high-performing investment property, this is a rare chance to acquire a premier Park Slope brownstone with both immediate appeal and lasting upside. You should live here!