OS Arch

Dave SiegertDavid Siegert, AIA – Principal Architect

1987 Bachelor of Architecture
Cal Poly State University, San Luis Obispo
Danish Royal Academy, Copenhagen, Denmark
CA Licensed Architect since 1994: #C-25191
American Institute of Architects
24 years professional work experience


Born in Southern California and reared in the high mountains of the Mojave Desert, Dave was drawn to the outdoors and quickly grew to appreciate the natural landscape and the contrasting differences in the way people lived.

With an aptitude for building and a refined artistic eye, Dave went on to study Architecture at Cal Poly, San Luis Obispo. During his studies there, he was selected to study overseas at the Danish Royal Academy through the University of Copenhagen. There, his focus of study was on adaptive re-use and social housing. It was in Denmark he embraced the philosophies and simple nature of modern design. After winning the Faellerparken Design Competition in 1987, he began developing partnerships with skilled artisans and craftsman throughout the US; teaming with them to design and build fine homes, furnishings and workplaces across the country.

Dave landed in Northern California and spent six years working as a senior architect and designer at Lail Design Group in St. Helena; applying his skills to winery and hospitality design. In the spring of 2011, he teamed up with his long-time associate Doug Osborn AIA, to form a new practice, Osborn Siegert Architecture [os-arch]. Together they continue to focus their attention on creating winery and estate architecture with customized functionality and site specific character.

Dave is a member of the Redwood Empire Chapter of the AIA and has had various articles published with regard to growth and design in the Bay Area and Sonoma County.

Selected Projects

Pura Residence

The French Laundry

Hall Winery: Petersen/Bergfeld

Distillery Building

Mattera Residence

Laird Family Estates Barrel Storage

Pahlmeyer Administrative Offices

Treasury Bistro

Bowman Residence

White Cottage

Ranch Winery

Tarman-Street Residence

Chanticleer Winery
(Use Permit)

Zialena Winery

Nickel & Nickel

New Production Building & Use Permit

Kitoko Winery

Scarlett Winery