Alchemy Architects’ latest prefabricated gem revels in the views of its Northern California landscape

By Joel Hoekstra

The client is a licensed architect. And the designer is an architect. So perhaps it’s no surprise that the panel of renowned architects that judged the 2016 AIA Minnesota Honor Awards was immediately enamored with the jewel-box residence that Alchemy Architects erected in Sonoma County, California, for B.J. Siegel, Apple’s senior design director for real estate and development.

Siegel and his wife purchased four acres of undeveloped land in Sonoma in 2014 and spent time camping on the site before deciding to build a weekend retreat. They wanted something small and economical but also well designed. “My overall desire was to have the simplest, purest result,” says Siegel. Their research eventually led them to Alchemy Architects in St. Paul, which in 2002 designed the weeHouse, a prefabricated home that the architects themselves built offsite and moved to its permanent location.

Working together long distance, Siegel and Alchemy founder Geoff Warner, AIA, developed plans for a home that could be built at a factory in Oregon and transported in sections to a slope with a stunning view on Siegel’s California property. After two concrete plinths were poured and prepared, a pair of prefabricated cubes were lowered into place by crane and bolted down in a single day. Both the primary living space (640 square feet, not including the deck) and the guest quarters (330 square feet) are tubular in nature, allowing untrammeled views of the landscape through glass walls.

Both boxes are clad in Cor-Ten steel, and the main cube dramatically cantilevers out over its foundation. Inside, walls, floors, and ceilings are covered with durable ipe wood. The larger cube contains a box within the box—a sleeping nook wrapped in whitewashed oak, which, like the larger structure, is open at both ends to accommodate the views. On one side of the “bed box” is the main living area, with a recessed flat-screen TV, a couch for lounging, a community table, and a galley kitchen furnished with IKEA cabinets. On the other side is a private space with a shower and toilet. The guest space, says Warner, is essentially a replica of the bigger cube, minus the living/kitchen area. Standing in for the bed box is a large oak wardrobe unit.

“We sited the house under a grove of trees, so there is some protection and shade from the sun in summer,” says Warner. The residence was fitted with a forced-air heating/cooling system, he notes, but most days the home can be kept comfortable by sliding back the glass doors and allowing the breeze to sweep through. Screens recessed into the ceiling can be lowered to keep insects out.

“Building a house that’s this minimalist comes down to a lot of stuff you don’t see,” says Warner. Details such as wall joints can stick out if they’re not handled sensitively. The architect and the architect client obsessed over the details—and they didn’t always agree. “I like things to be slightly asymmetrical,” says Warner, “but B.J. likes to line things up. In the end, we both compromised a bit.”

Siegel says he and his family are delighted with the results. “The ability to do this teeny modest house was a dream. And it turned out to be more wonderful than we even thought possible,” he says. “When you’re out there, you hear only the birds and the wind. It’s very remote and yet only an hour away from the city. It’s such a privilege to live there.”

Location: Santa Rosa, California
Client: B.J. Siegel
Architect: Alchemy
Principal-in-charge: Geoffrey C. Warner, AIA
Project lead designer:  Geoffrey C. Warner, AIA
Factory for modular build: Fidelity Builders
Size: 640-square-foot main living space plus 330-square-foot guest quarters
Cost: $450,00 for modular, $150,000 for site work
Completion: October 2015
Photographer: Geoffrey C. Warner, AIA

“It’s using the beauty of the site and setting up a platform that’s all about living in the moment. The incredibly beautiful site and the specificity of built pieces are really distinct and different—the site and the structure are doing a lot for each other in that distinction.”

“That lovely shallow stairway, where it’s structured platform to platform without touching the ground. There are gorgeous details like that throughout.”

“Yeah, I think it should be an Airbnb. It’s beautiful.”