Bill Koch Sells Historic Cape Cod Home for $20 Million
Bill Koch has officially sold one of Cape Cod’s most historic private estates for $20 million, closing the chapter on a property with years of American social and political history.
Koch purchased the estate in 2013 for $19.5 million, acquiring a home he had admired decades earlier while visiting the Cape in the 1970s, when it was still owned by its legendary prior owners.
Those prior owners were none other than Paul Mellon and his wife Bunny Mellon, the influential designer behind the White House Rose Garden.
During the Mellons’ tenure, the estate became a refined summer house, hosting world leaders, movie stars, and close friends, including John F. Kennedy and Jacqueline Kennedy Onassis. Their legacy remains deeply embedded in both the home and its landscape.
Property Highlights
Price: $20 million
Location: Cape Cod, Massachusetts
Size: 7,310 square feet
Lot: 7.43 acres
Bedrooms: 8
Bathrooms: 9
Notable Features: Private island setting, 500+ feet of waterfront, private dock, historic gardens by Bunny Mellon, beach house, converted art studio guest suite
Inside The Mellon Estate
Robb Report and Christie’s Real Estate offer a closer look inside The Mellon Estate.
The roughly 7,300-square-foot main residence is carefully integrated into its natural surroundings, with eight bedrooms facing either sweeping sea views or the gardens.
The estate unfolds with winding paths that connect the main house to multiple cottages, including a former art studio transformed into a private guest suite, and a separate beach house used for entertaining along the water.
With more than 500 feet of shoreline, a private dock, and access to an adjacent private island now preserved as a protected bird sanctuary, the estate offers a level of privacy rarely found on Cape Cod.
Overall, the setting combines refinement with a relaxed coastal lifestyle, echoing the understated elegance that defined the Mellons’ summers and later drew Koch to the property.
Bunny’s Famous Gardens
Bunny Mellon’s influence is evident throughout the grounds. Her approach favored restraint and natural beauty, layering native plants, orchards, and specimen trees to create a landscape that feels effortless yet deeply curated.
Her work isn’t just scattered throughout the landscape, but a significant portion of the property is devoted to formal gardens, including a greenhouse and a garden shed that likely housed the tools and materials Bunny used to maintain the estate.
Video Tour
A more detailed look at the entire estate, from Bunny’s gardens to the sandy path leading to the beach, can be seen in a video tour from LandVest Real Estate, which highlights the flow and sheer expansiveness of the property.
Why Did Koch Sell?
In the end, the decision to sell wasn’t about leaving Cape Cod behind, but about re-sizing a portfolio that had grown alongside a lifetime of collecting historic properties.
The Mellon Estate had long served as overflow space for family and guests, while Bill Koch continued to live next door in his primary Cape home, which he has said is now more than sufficient for hosting on its own.
With that need gone, the historic property simply became surplus to a lifestyle that no longer required two neighboring estates.
The sale also fits into a broader period of consolidation for Koch, who maintains major holdings across the country, including his expansive Aspen estate currently listed at $99 million.
