Existing buildings are given new life through adaptive reuse interventions that are transformative. The greenest building is the one that already exists, and adaptive reuse provides opportunities for design leadership: being able to make imaginative proposals in existing structures means fewer buildings on greenfields. A rain pit pools water away from trees to ameliorate flooding. Exterior rearrangement of wall openings and interior rearrangement of partitions is motivated by both design investigations and cross-ventilation strategies that increase air circulation in this writer’s residence. Coordination of form and program fills the spaces with ample and varied daylight.