The Hamptons aren?t exactly known for being discreet. This grouping of hamlets and villages on the eastern tip of Long Island is renowned as a summer enclave for celebrities and other wealthy New York City residents, with ostentatious luxury cars clogging up country roads that are totally quiet in other seasons. Beach house rentals can cost upwards of $400,000 for a single month, and glitzier residences tend to shout their price tags all the way down their long, winding driveways.

While much of the architecture does draw, at least marginally, upon the local vernacular, as well as the historic character of humbler eastern Long Island structures, it often does so in the form of sprawling floor plans, multiple tennis courts, and wide swathes of manicured, topiary-spotted lawns. But look beyond the flashy mansions, and you?ll find a breezy, laid-back beach town culture full of permanent middle-class residents ? and at least one high-end weekend getaway that aims to set a good example for seasonal guests. To achieve such an effect, the couple behind that getaway approached New York City-based interior design and architecture firm Mapos in hopes of finding the antidote to stereotypical wealth-flaunting Hamptons homes.

Owners of a global French beauty brand, the clients wanted a timeless, multi-generational family retreat that paid tribute to its sensitive shoreline building site, incorporated the latest sustainable technology and design strategies, and exuded a streamlined c...