Seadrift Lagoon, Stinson Beach, CA

“The form of the house is not amorphous, not a free-for-all form. On the contrary, its construction has strict boundaries according to the scale of your living. Its shape and form are determined by inherent life processes.”  


–Frederick Kiesler


The Time-Motion House evolved from our research practice and uses a process of “Intuition as Method” to explore new forms and spaces for temporal habitation. The house is primarily a vacation house and time-share rental property for one of our long-standing clients, Dr. Bill Longwell. Located on the beautiful Seadrift Lagoon adjacent to Stinson beach, the owner wanted a custom designed house with one large open entertainment space adjacent to a master bedroom and additional sleeping area for guests.


Inspired by the location on the Seadrift Lagoon among a series of very well published homes, we aimed to develop a signature property that utilized the most innovative research and design techniques available. While canoeing on the lagoon adjacent to the property, we saw the potential to generate a series of roof forms that might appear to move or be animated by the surrounding natural landscape. In light of our theoretical work in computer animation generated design, and continuous tension shell technology and organic form, we proposed to design a building using a series of curvilinear roof forms that would be generated to support a large space with adjacent smaller spaces all under one continuous roof or home.


Using measurements of existing and projected movement through a series of diagrammatic time-motion studies of daily circulation and use patterns, we designed the shape of this space parametrically. Size, shape, and form of a continuous complex curved roof conformed to an evolving set of parameters. We then added ecological criteria to develop the final shapes of the roof forms. We curved, shifted, pulled, ripped, expanded and contracted the roof surfaces in correlation to environmental forces of wind, sun, water, and view angles of the distant hills. To let sun in for heat and light we raised the roof for example; to protect the house from winds and western light we lowered the roofs. The final shape of the house modulates to its surroundings—geared to daily habits of work, rest, and play.


We originally conceived the complex curved roof as a continuous tension shell in concrete, plastics (fiberglass), or wood. We then researched CAD/CAM CNC milling of high-density rigid foam for the interior core, and sheathed in plywood or fiberglass to serve as the structure and insulation. Professor Martin Bechtold of Harvard University provided examples of sandwich panel designs in wood to the client. However, we eventually designed an alternative cost-effective structure in plywood developed in consultation with Dr. Anders Carlson of GMS Engineering INC. in Los Angeles. The final design took advantage of advanced CAD/CAM CNC milling processes to readily construct plywood truss joists and the roof diaphragm. Adding to the design to create expansive glazing on the North side of the house adjacent to the view and the water we adapted two lateral systems using Simpson Strong Walls and structural steel mullions. We designed the floor using continuous terrazzo surfaces, and a unique kitchen island made of a series of form fitting mobile stations for different cutting needs (marble, wood and stainless steel).

Principal Designer and Architect: 

Stephen Phillips, AIA, Ph.D

Project Team: 

Rogan Ferguson, Cam Helland, Stephen Becker, and Katsu Shegemi


GMS Engineering INC (Structural)
BEC Associates (Title 24)