For a house in Sag Harbor, New York, designer Benjamin Vandiver mixed a client’s multifaceted art collection with modern, midcentury, and vintage furnishings.

An Alexander Calder artwork surmounts a Pierre Paulin sofa for Ligne Roset that is upholstered in a Pierre Frey mohair. The Ico Parisi side table is topped by a midcentury ceramic Vallauris Kostanda table lamp, and the cast aluminum cocktail table is by Chris Wolston.

Little Smoke, Mt Washington (2016) by Celeste Dupuy-Spencer hangs alongside a selection of Picasso Guernica lithographs in a Sag Harbor house designed by Benjamin Vandiver.

A Cristina BanBan artwork is seen in a Hamptons home designed by Benjamin Vandiver, who also installed a Lawrence Peabody lounge chair for Selig that is upholstered in a Dedar velvet, a Senufo drinks table, and a Studio Woven mohair rug.

A BDDW Sev-Drullo sofa joins a Joseph Inco lounge chair and a late 20th-century French cocktail table.

A vibrant Jana Schroder canvas animates a serene living area outfitted with a Vladimir Kagan sofa and Jacques Blin table lamp, plump Michel Ducaroy Marsala chairs, and a Charles Dudouyt dining table that’s paired with Pierre Jeanneret chairs.

A lounge area flooded by natural light is outfitted with a Paul Evans cocktail table, a Robert Motherwell work on paper, and Picasso lithographs.

A playful gathering spot in the Hamptons home boasts a Ligne Roset Togo sofa as well as artworks by Chloe Wise and Marria Pratts.

An 18th-century Provencal doorway frames a bed accompanied by a 1950s French wood stool and a Maynard Monrow artwork.

A cozy sleeping alcove in the Sag Harbor, New York home.

A custom outdoor dining table is covered in grass-green zellige tiles and surrounded by vintage French oak chairs; above, a shapely Venetian chandelier by Richard Mishaan for Urban Electric illuminates the space.

The house in Sag Harbor previously belonged to designer Steven Gambrel as well as antiques dealer Jill Dienst of Dienst + Dotter.