This off-grid, tiny prefab cabin is designed to adapt to any environment

written by Melissa Dalton | photography by Andrew Pogue

As an architect, Matt Wittman thinks a lot about how to get people out of the house. That’s always been the ethos behind the work of his Seattle firm, called Wittman Estes, co-founded with landscape designer Jody Estes in 2012. Their manifesto is that architecture and nature should be considered an “interconnected whole,” rather than separate entities. “We’re always trying to make buildings where you spend as much time outside as you spend inside,” said Wittman.

What does that look like in real life? In 2007, Wittman and Estes’ own Seattle property started as a small home on a deep city lot, to which they added a new studio outbuilding connected by an exterior courtyard and covered breezeways. More recently, they honed their approach on this forested Whidbey Island site, when the owner of a tech startup asked them for a customizable prototype for a small, off-grid cabin fused with nature.

Having designed many cabins for remote locales across Washington, from the San Juan Islands to the Cascade Mountains, Wittman had encountered the same problems over and over. Sometimes it was the difficulty of finding a construction firm that had experience with high-performance buildings, in order to achieve such metrics as Net Zero. Sometimes, the problem was the damage to the natural environment caused during the construction process. “The question became, ‘How do we build something high quality and low impact in an ecologically sensitive area?’” said Wittman. Their solution is called the Puzzle Prefab.

Pull It Apart

The designers started by breaking up the home into three modules: living/cooking, sleeping/study and outdoor dining. Each module is assigned to its own container and then connected by covered walkways and outdoor spaces. Modules are kept 12 feet wide, so as to be easily transported on the back of a truck, and can be configured in “an infinite number of ways,” said Wittman. “We wanted to come up with a living solution that could be flexible, customized through its configuration and adaptable to any site”

Prefab

Prefabricated construction means the home is built in a factory, trucked to the location and craned into place once the site has been prepped for utilities and a foundation. This allows for precision and efficiency, says builder Sparrow Woodworks of Indianola, and less site disruption, as the modules are delivered 95 percent complete. “That was a really exciting day,” said Wittman of the cabin’s installation. “One day we have nothing, and then by the end of the day, all the modules are there.”

Puzzling Out the Details

For such a small building—the interior is just 600 square feet—it has mighty green credentials. Triple-pane windows, advanced air sealing techniques and a robust insulation envelope allow it to exceed energy code standards, while a 4.1-kilowatt solar array supplies energy needs. Rainwater is gathered in a 900-gallon tank before being purified by a custom filtration system and sent for potable use to the kitchen, bathroom, shower and dishwasher.

Even the building’s foundation treads lightly, as it uses zero concrete, reducing the carbon footprint by 77 percent, said the firm, who instead placed the home atop handset micro pin piles designed to reduce earth disturbance and conserve nearby tree roots. An integrated greenhouse provides household veggies and uses the thermal properties from the adjacent mechanical room.

Last but not least, all interior finishes and components, from the FSC-certified wood to the bioethanol fireplace, are Red List-free. (The Red List is a list of chemicals typically found in building materials, and deemed to be unhealthy for humans and the planet as compiled by the Living Building Challenge.)

Double Duty

As for combining inside and out, Wittman notes that the cabin has an equal amount of indoor and outdoor space. “When you pull the house apart like this, that was a way of creating inbetween spaces, and linking them with outdoor walkways and covered patios,” said Wittman. The covered walkways then do stealth double duty, with roofs that sport solar arrays and rainwater collection downspouts integrated into the steel structural columns of the canopies.

Inside, every room or corner has a direct view of nature, whether it’s the skylight over the bed for stargazing or the frosted glass door in the shower that opens to the forest. The cozy factor, in things like the built-in couch that doubles as a pull-out bed, is balanced by the pull to go outside. Doing everyday activities, like taking a cup of coffee from the kitchen to the dining table, involves a short stroll through the woods.

It all works together to make it so the home lives much larger than its small footprint, something that Wittman noticed on his first walk-through when construction was complete. “I was surprised at how generous it could still feel because of the placement of the windows and the flow of movement between the modules, and the way that the materials are warm and welcoming” he said. “It really doesn’t feel like a tiny home”