For decades, design/build firm Bensonwood Homes has demonstrated that factory-built homes can be beautiful, original, and high-performance. From a collection of engineered net-zero dwellings to a shop-fabricated LEED-Platinum prototype, all homes from this Walpole, N.H.-based company are built to exacting standards of sustainability, efficiency, and livability.

Its newest creation, a timber-frame dwelling in Weston, Conn., shows that pre-fab construction can offer all of the design flexibility of a site-built custom home.

The owners' vision, a contemporary take on the classic New England barn, was achieved through the use of simple, rustic materials such as exposed Douglas fir timbers, steel hardware, and vertical barnboard siding. Modern touches such as the open floor plan, state-of-the-art kitchen, and vaulted ceilings lighten and brighten the farmhouse aesthetic.

Through oversized windows and glass double doors, natural light floods the large south-facing entry foyer, where the sun's warmth is absorbed by the thermal mass of the slate floor tiles.

Architect Chris Adams fine-tuned the window selection to the home's orientation, with double-glazed 0.33 U-factor south-facing windows and triple-glazed 0.2 units for the northern side. For much of the fall and some of the winter, heating is provided only by the centrally located Tulikivi wood-burning fireplace. Made of Scandinavian soapstone, the heat-accumulating firebox radiates warmth for up to 24 hours after a fire is put out, so Adams located an air return close by to help circulate the warm air throughout the house.

But it's the factory-built nature of the house that provides the most energy-efficient benefits, achieving an engineered, airtight home (1.76 ACH@50Pa) while saving time and money during the construction process, Adams point out. "With factory construction, it's the quality of the connections and how well the pieces go together that make for a very tight building."

In addition, the home is sealed with a European gasketing product instead of foam where the walls meet the deck, the roof meets the walls, and around windows and doors. The foam rubber material from Trelleborg ensures an airtight seal at every intersection of the building envelope and retains its resilience even during shifting and through seasonal expansion and contraction, Adams says.

Other sustainable features include a Renewaire ERV for fresh indoor air, dual-flush WaterSense-certified toilets, and an Energy Star-rated Voltex hybrid electric heat pump hot water heater from AO Smith.

The one-of-a-kind dwelling also benefits from the Open-Built integrated process used for all Bensonwood homes, which takes a layered design approach that allows owners to easily move or remove walls or access fixtures and wiring to adapt to the changing needs of occupants. "This home is a custom project unlike any other we've done, but it shares its DNA with previous projects," Adams says.

Jennifer Goodman is Senior Editor for EcoHome.