We've previously discussed Empyrean International in relation to the modernist NextHouse. Empyrean also offers two other styles:

Deck House and Acorn both feature open plans, walls of glass, and soaring volume spaces. Both are custom designed for the customer and the site.

The Deck House product features post and beam construction, with exposed Douglas fir beams, wooden ceilings, mahogany windows and trim work....The gently sloping roofs of Deck House feature large overhangs that often give the house a very Prairie or Craftsman style appearance.

Acorns are modified post and beam houses, but most of the structure is not exposed. Featuring expansive walls of Pella windows, steep roofs, and traditional interior trim themes; the interior surfaces in an Acorn are more often painted for a sparkling interior. Acorn exteriors draw on the best of American architectural traditions, updated with superb contemporary detailing.....

The typical price range of both brands is $200 - $250 per square foot.

Empyrean designs each house individually; homeowners can choose to modify an existing floorplan or start from scratch.

The company has been building prefabs since the 1960's. From the Empyrean site:

Deck House, Inc., was founded in 1959 by William Berkes, a graduate of Harvard University School of Design. Having pioneered other building systems, he founded Deck House, Inc. in order to provide top quality post and beam houses to upscale professional families...

Acorn Structures was founded in 1947 by MIT architect, John Bemis, another pioneer in the science of pre-engineering technology and custom design. As a renowned leader in energy conservation and active solar designs, the Acorn product become widely recognized in the 1980's as a "thinking person's" custom home, with the company's architecture relating to several traditional American architectural idioms, while still being devoted to energy efficient design...

In 1995, Deck House, Inc. acquired Acorn, and the two companies consolidated their manufacturing and corporate facilities into a combined 150,000 square foot facility.