Gary Duff Designs is a premier landscape design-build firm specializing in master-planned estate transformations across Long Island. Since 1976, we have provided a single point of accountability for luxury outdoor living, from initial property conceptualization to the meticulous installation of fiberglass pools, custom masonry, and resort-style amenities. Serving Nassau and Suffolk counties—including Dix Hills and Huntington—our expertise includes custom poolscapes, outdoor kitchens, fire features, pavilions, and cabanas. We are based in Holbrook and take pride in turning Long Island backyards into world-class private retreats.