At 12,000 square feet, the Cove Hollow Farm Road Residence is more akin to a compound. The same family has occupied the property for generations, each one leaving its own imprint on the place. A new expansion by New York’s Architecture Outfit (AO) aims to knit the old and the new.

AO principals Thaddeus Briner and Marta Sanders treated a 2,000-square-foot farmhouse, more than a century old, like a family heirloom—something to preserve but also be stowed away. “We relocated it with careful consideration for its appearance from the road as well as the integrity of the timber framing itself,” said Sanders. “We then situated a spacious contemporary home, pool house, and landscaped areas sensitively around the historic structure.”

The new buildings and gardens travel along a central axis. In keeping with Hamptons traditions, cedar shingles clad the new buildings, in this case an elegant Alaskan yellow that doesn’t darken the minimal blackened-steel framing of the glass window walls. The glass encases the living area, which sits between a formal lawn and an organic garden. A sunken lounge offers views of sumptuous perennial gardens. Yet more greenery can be found by taking the stairs to the second floor’s open reading area and bedrooms resting by the rooftop’s allotment of succulents.

It’s not all verdancy, though the project is exceptionally green. (“The site is served by a new geothermal wall; the houses incorporate energy-efficient mechanical systems and high-performing envelopes designed to withstand seaside storm conditions,” said Briner.) The kitchen, for example, conceals its storage and appliances within invigorating cabinetry painted a bold Atlantic blue. It’s the same hue as the front door. By contrast, bathrooms are clad in classic West Coast Heath Ceramics tile.