About Us










Stephen A. Biggs, S.E., President

As President of Biggs Cardosa, Stephen Biggs brings more than 40 years of experience in leadership for the management, design, and construction of large and complex projects involving both building and transportation structures. His experience and expertise provides significant value to our clients in developing structure concepts and providing value analysis for the design, modification, rehabilitation and seismic retrofit of these structures, and how those structure concepts are integrated into the overall project.

 Steve has managed large and complex projects requiring integration and coordination of the work of multiple disciplines. He specializes in project management, concept development, and value engineering for the design and seismic retrofit of a large variety of structures. Some of his most notable transportation design experience includes Highway 17/85 Interchange in San Jose, BART Extension to San Jose, Tasman Corridor & Aerial Guideway in Milpitas/San Jose and the Jefferson Avenue Grade Separation in San Mateo. Steve's building experience includes Santana Row in San Jose, Bay Street in Emeryville, San Mateo Parking Structure expansion and retrofit, and the Seismic Retrofit of the historic St. Joseph's Cathedral in downtown San Jose. 

 Steve is registered as a Structural Engineer in the State of California.


Mark A. Cardosa, S.E., Executive Vice President

With over 40 years experience as a structural engineer specializing in the design of numerous building projects. Mark Cardosa has been involved on a wide variety of projects including public, commercial and industrial buildings.  Mark specializes in the design, modification, rehabilitation, and seismic retrofit of these structures.

Mark has experience with many different building systems and structural materials that have been used successfully in the past.  He has worked on projects that require in-depth understanding in architectural, mechanical, plumbing and electrical systems working closely with consultants of different disciplines to deliver satisfactory products to his Clients.  Mark’s experience with public, commercial, institutional and industrial clients provide him with the understanding of the process and perspectives that Owners may have on their projects.

Mark is registered as a Structural Engineer in the State of California.


Daniel B. Devlin, S.E., Principal

Dan Devlin has been with the firm since its inception.  Dan has been responsible for managing the design of numerous building and bridge structures throughout California.  His varied experience includes preliminary engineering studies, project design, construction document preparation, construction administration, and project management for both public works infrastructure and private projects. In addition, he brings project management experience with multi-disciplined engineering projects that will ensure an immediate response to any project challenge.

Dan currently acts as Chief Engineer for the firm which involves improving uniformity of design approach between design teams and design offices, and identifying, defining, and standardizing the use of analysis and design tools.

Dan is registered as a Structural Engineer in the State of California.


Mahvash M. Harms, S.E., Principal

Ms. Harms has over 25 years of Project Management and Structural Engineering experience.  Her project management and design expertise include many multi-disciplinary building and bridge projects for diverse clients, including VTA, Caltrans and many other public agencies.  Since joining Biggs Cardosa Associates, Ms. Harms has led the design of major building and transportation related projects.  Her transportation related experience includes Route 85/87 Interchange, SR 152 /SR 156 Interchange, many structures along Highway 101, 237 and other highways throughout California as well as seismic retrofit of numerous bridges.

Ms. Harms’ building project management experience includes seismic retrofit of the BART Rockridge Station, seismic retrofit of four County of Santa Clara Court facilities, design of the Vector Control Service Yard, and design of several new fire stations throughout California. 

Mahvash is registered as a Structural Engineer in the State of California.


Roy M. Schnabel, P.E., Principal

Roy joined the firm shortly after receiving his Bachelor of Science degree in Civil Engineering from Santa Clara University in 1987.  He has over 27 years of experience in structural engineering with an emphasis on transportation and infrastructure projects.  He has managed numerous projects including new construction, rehabilitation and/or seismic retrofit of various pedestrian, vehicular, and rail bridge structures, retaining wall and soundwall structures, and various hydraulic structures including tanks, pump stations, junction boxes, floodwalls, drainage channels and creek trail facilities.

Roy acts as Project Manager for multi-disciplinary projects.  In this role his responsibilities include coordinating all roadway geometrics, channel work, traffic control, construction staging, utility coordination and relocation and environmental issues associated with the projects including close coordination with VTA, Caltrans, cities, counties, water districts, Army Corp of Engineers, Department of Fish and Game, utility agencies and various other government agencies.

Roy is registered as a Professional Engineer in the State of California.


Michael A. Thomas, S.E., Principal

Michael has been with the firm since 1989, shortly after graduating from Santa Clara University where he received his Bachelor of Science degree in Civil Engineering. During his tenure with the firm, he has led the design of over 80 bridge projects, representing well over 200 individual bridges, including PS&E and Advance Planning Studies (APS) for both PSR and PA/ED documents. Projects have included everything from bridge widenings, seismic retrofits, and bridge repairs, to multi-structure interchanges and long aerial viaducts. One of Michael's specialties has been the design of rail structures. He has led the design of numerous grade separations, underpasses and overheads of heavy rail, light rail, BART tracks and High Speed Rail. 

Michael is the Principal-in-Charge of our Fresno, Oakland and Orange County offices and leads one of the bridge design teams in San José. 

Michael is registered as a Structural Engineer in the State of California.