11 Bay Avenue 1-Acre Building Lot in Water Mill, NY - Fully Approved Plans & Permits. A rare opportunity to build a modern Hamptons retreat in the heart of Water Mill. This one-acre property is delivered with fully approved plans and permits for a 7-bedroom, 8-bathroom luxury residence totaling 6, 284 sq. ft., plus a 2, 755 sq. ft. finished basement. In addition to the approved plans, the seller has developed an alternative modern design concept accompanied by a complete interior design package - offering a turnkey vision for a contemporary and elegant home. The design emphasizes open living spaces, abundant natural light, and a seamless indoor-outdoor flow, all complemented by a private pool area ideal for entertaining and relaxation. With all approvals in place, this project is ready to break ground immediately. Located south of the highway in one of Southampton's most sought-after enclaves, this offering is ideal for developers, investors, and end-users looking to build their dream Hamptons home.