Owner-built in 2005 and being offered for its first sale since construction, this oversized 0.63-acre Ronkonkoma property delivers rare scale, volume, and versatility. 471 Southport Street features 10-foot ceilings, abundant natural light, central HVAC, and quality construction details including 6-inch walls. The layout supports today's need for space, privacy, dedicated work areas, and room to spread out. The main and second levels offer 5 bedrooms and 3 full baths, with expansive living and dining areas designed for daily comfort and entertaining. The spacious kitchen features a center island, breakfast area, granite counters, stainless steel appliances, and access to the deck and deep backyard with room for outdoor enjoyment, recreation, or future improvements. Upstairs, the oversized 25' 3" x 25' 0" bonus room provides exceptional flexibility as a family room, media lounge, playroom, gym, home office, or potential reconfiguration opportunity, subject to proper approvals. The primary bedroom features tray ceilings, a walk-in closet, and a generous feel. A major value-add, the lower level includes a legal accessory area per CO with 2 bedrooms, full bath, kitchen, and separate entrance — ideal for extended household living and lifestyle flexibility. Buyer to verify intended use. With approximately 4,683 sq ft total per provided floor plan, a two-car garage with extra-wide bays, garage sink, basement access, and driveway parking for up to 8 cars, this home offers a rare combination of interior scale, lot size, and adaptability. Come experience the ceiling height, light, and scale in person — this one truly lives large.