High Horse Ranch Prefab Modular House, California

The living-dining-kitchen space and attached patio are the social center of the project and overlook the expansive southern view.

About KieranTimberlake
About Moderna Homes
About Bent Level Construction

Project: High Horse Ranch
Architect: KieranTimberlake
Main house area: 2,580 square feet
Two guest cabins area: 290 square feet
Year: 2016
Builder / General Contractor: Buckeye Construction, Moderna Homes
Location: Willits, California
Structural Engineer: CVM
Civil Engineer: Adobe Associates
Lighting Design: Sean O'Connor Lighting
MEP Engineering: Engineering 350


AIA California Council Merit Award
AIA Pennsylvania Honor Award
AIA Philadelphia Merit Award

Description by architects

How can we orchestrate an intimate experience of nature while treading lightly on wild terrain?

Accessible only by winding gravel roads, the site for High Horse Ranch in California's Mendocino County is full of steep slopes and open meadows. The owners were struck by the dramatic experience of approach and arrival, where the edge of a cliff falls away and reveals a panoramic view of the forested valley below. Accordingly, the design was driven by their early vision of the guest experience: a long, climbing drive; a short, shaded walk to a sheltered welcoming area; and then, upon entering the house and rounding a corner, taking in the view.

The design evolved from a concept of how guests would approach the site and experience nature first hand. The site features steep slopes and vegetated areas of open meadow, manzanita thickets, and forests of oak, Douglas fir, and madrone.

A main house overlooks the valley and two guest cabins are carefully perched on natural, undisturbed clearings in the woods. The two cabins are satellites tethered to the main house's center of gravity, sharing its material palette of reclaimed wood, cor-ten steel, and floor-to-ceiling glass. The cabins depend on the main house as a meal-time and social gathering place, but each offers guests unique vantage points and the privacy of a standalone bathroom, desk, covered porch, and fire pit.

The main house is organized around a central living-dining-kitchen pavilion used for socializing and a more private bedroom-study pavilion. These spaces are designed to keep residents immersed in nature, with rooms defined by natural clearings and trees instead of walls and windows.

Intrigued by the precision and innovative design of Loblolly House, the owners favored building techniques that would touch the site lightly and reduce construction waste. As a result, the design uses off-site modular construction throughout with varying degrees of fit-out. The main house is comprised of two primary and 11 secondary modules, while the guest cabins are made from single, mostly-completed modules craned into place and set onto concrete piers. The factory-built modules were carefully transported up winding roads and set in place without harming a single tree.

The guest cabins are nestled into pocket clearings and offer unique views.

Guest cabins share a the main house's material palette of reclaimed wood, cor-ten steel, floor-to-ceiling glass, and stacked firewood.

Guest cabins open completely to the outdoors with cross-ventilation through clerestory windows.

Tucked in the hills of Northern California, High Horse Ranch is a private residence consisting of three structures. The main house sits at the highest point of the site in a natural clearing.

The understated entry to the main house is a precursor to the vistas seen indoors.

The kitchen is central to the main pavilion of the main house and organized around two generous islands.

To pre-cool air entering the house, the main house employs an evaporative mister system integrated into the outer edge of the roof overhang.

Custom steel plate connections transfer lateral loads from the roof to the shear walls.

Natural light floods the gallery through a hidden clerestory.

The master bedroom is entirely glazed on two sides with large doors that open to the exterior. A skylight directly above the bed allows stargazing before sleep.

Rooms were designed to be defined by their natural boundaries, such as tree lines and views, instead of by their walls and windows.

A patio and fire pit create an outdoor room overlooking the valley below.


Inspired by our book on Loblolly House, clients in California asked us to design an off-site fabricated home uniquely tuned to their steeply sloped site in the mountains of Mendocino County. The clients, a physician and a Silicon Valley electrical engineer turned artist, envisioned the home as a weekend getaway from San Francisco. It includes a 2,600 square-foot house and two free-standing studio structures of 300 square feet each.

A spectacular view of the mountains of Mendocino County, California, from the roof of High Horse Ranch.  

The modules for this weekend retreat known as “High Horse Ranch” were built by Moderna Homes within their workshop in San Jose and delivered to the remote site on flatbed trucks.

The modules were transported by truck up winding roads to the heavily wooded, mountainous site. 

Over the course of two days, the modules were carefully set on site by Bent Level Construction, who successfully negotiated the rugged terrain and avoided damage to vegetation.

A studio is lifted in order to be carefully positioned atop four piers.

A single module comprising each studio was first lifted into place with the use of a crane and positioned atop a foundation of four concrete piers. The thirteen modules and roof panel of the main house were then maneuvered by trailer and craned into place, beginning with the main circulation and service spine at the center of the home.

A studio module meets its foundations. 

While Loblolly House made use of a skeleton of scaffolding inserted with blocks and cartridges, High Horse Ranch is comprised entirely of modules. They are of two basic types: enclosed, service-intensive modules that form the spine of the home, and large, open modules that form the living spaces. The latter are infilled with glazing to offer views of the landscape.

The first module of the main house is positioned and lowered onto the foundation.

Modular construction was pursued for this project in order to minimize disruption to the 40-acre site, allowing us to touch the landscape only lightly and to preserve the meadows and wooded slopes. No trees were harmed during the process: an eight-inch section of a single dead branch was the only tree cut over the course of the two-day set.

A view from below: Workers help ensure a module of the main house lands in place as it is lowered by crane. 

The final steps include making electrical connections across modules, adding the roof, creating a water-tight weather barrier, and completing the finishes and cladding. This on-site work is being managed by Buckeye Construction.

About KieranTimberlake

The alchemy of art, science, analysis, and intuition with regard to the built environment is our core mission.
Founded in 1984, KieranTimberlake brings together the experience and talents of over 100 professionals of diverse backgrounds and abilities in a practice that is recognized worldwide. Our projects include the programming, planning, and design of new structures as well as the conservation, renovation, and transformation of existing buildings, with special expertise in education, government, arts and culture, civic, and residential projects.

Common to all our work is that each project begins with a question and continues its development within a culture of continuous asking, ensuring that design results from deep investigation. KieranTimberlake is committed not only to delivering the highest quality services to our clients, but also to pursuing ideas that push the practice of architecture forward.

We have received hundreds of design citations, including the Firm Award from the American Institute of Architects in 2008 and the Cooper-Hewitt National Design Award for Architecture from the Smithsonian Institution in 2010.

Address841 N American St, Philadelphia, PA 19123, United States

About Moderna Homes

Address558A Santa Cruz Ave, Menlo Park, CA 94025, United States
Phone+1 650-391-9805

About Bent Level Construction

PJ Humphrey, owner of Bent Level Construction, Inc., has been in the industry since 1973. His Father Pat Humphrey started in the early 60’s. PJ went to work with his father on weekends and during the summers, growing up and learning the trade.

With a growing sense of independence and confidence in his ability, PJ struck out on his own in 1980. In 1992 Bent Level Construction was incorporated.

Bent Level Construction was always called on for the more difficult jobs, which made them experts in the industry. PJ Humphrey accepted the challenges, and to this day, Bent Level Construction is known in the industry as one of the best in the business.

AddressMolalla, OR 97038, United States
Phone+1 503-650-5883

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High Horse Ranch Prefab Modular House, California