Mike O’Brien began his career in the construction industry immediately upon graduation in 1974 from St. Mary’s College in Moraga. From construction laborer to founder and owner of the commercial construction firm of O’Brien Builders in 1989, he excelled in all levels of the construction experience. Before founding O’Brien Builders, Mike worked as a labor foreman, carpenter, purchasing agent, estimator and project manager for three distinguished commercial construction firms in the East Bay Area. From 1977 through 1989, he worked for the Hofmann Company of Concord, The Zimmerman Company of Lafayette, and again in Concord for BCI General Contractors. His experiences and training through-out this period was solely in Commercial construction. Projects included Class A office buildings, seismic retrofit work, building renovations, tilt-up construction, site civil improvements, tenant improvements and medical improvements.

In November of 1989, Mike started O’Brien Builders which has developed and prospered as a commercial construction company, providing services in all phases of the commercial construction field. O’Brien Builders is solely owned by Mike O’Brien and solicits work generally in the private sector. Contracts are secured following competitive bidding, select-list bidding, and negotiated processes. The appreciated personal characteristics of Mike O’Brien drive and command how O’Brien Builders is perceived by a long list of satisfied clients. Integrity, honesty, and dependability are the driving forces behind the success Mike has brought to his company.


Project Manager

Jack is the newest member of the O’Brien Builders team. He came aboard in the summer of 2021 and is projected to be here for quite some time. He is excited to be working within the O’Brien Builders’ organization. He graduated from the Cal Poly San Luis Obispo, School of Construction Management in 2016, and then spent 5 years in supervisory and management positions at Lendlease (U.S.) in San Francisco. Jack’s projects at Lend Lease centered on high-rise, mixed-use residential buildings. He brings great experience and contemporary attitudes to O’Brien Builders. His new-generation abilities and technical skills will enhance the project management here at O’Brien Builders.


Office Manager

Julie has been with O’Brien Builders for over 12 years. In that time she has moved from general administrative assistant to the Office Manager role, as well as handling all of the accounting duties for the work to pass up to the Controller, Pierre Sene. Julie has excellent organizational skills and is the most detail oriented when it comes to working with numbers. She has complete control of the subcontractor billings and her owner billings are always accurate. Her value to O’Brien Builders cannot be understated.


Administrative Assistant

Courtney started with O’Brien Builders in May of 2022. She spent the previous 5 and a half years working for Electric Tech Construction telecom company in Concord, CA, . There she started as an Administrative assistant and worked her way up to be the HR Coordinator and Payroll assistant. Prior to that she attended Tennessee Technological University and received her B.A. in Criminal Justice & Sociology. Courtney lives locally in Solano County and has brought a great strength to the OBB team. She has excellent organizational and communication skills. We look forward to her growing with us.



Pierre Sene brings a distinguished background in accounting to O’Brien Builders. Pierre has earned a Bachelor’s Degree in Macroeconomics Planning from the University of Dakar in Dakar, Senegal and holds a Masters in Business Administration from San Francisco State University. Pierre’s extended education includes credits for Construction Management, Change Management, Cost Accounting and various other business management courses. As a Controller,

Pierre, has worked for several construction and engineering firms in the Bay Area. Past firms include a concrete supply company, a windows manufacturing company, a paving and grading contractor, and a residential development firm / contractor, all over a 10-year period. Pierre’s activities outside of work are a reflection of his strong performance and driven attitude. As a two time Judo Olympian; Five time US Masters Judo Champion and a coach of over 15 years, Pierre brings a strong leadership role to O’Brien Builders.





Mr. Bergen came to work for O’Brien Builders in 2001, with a solid background in construction supervision. For two years prior to O’Brien Builders, Marty was the lead superintendent for American Restaurant Group, building restaurants through-out Northern California. Prior to ARG, Marty filled the same shoes for ResCom of Vacaville for 4 years. During these six years of restaurant specialization, Mr. Bergen experienced and excelled in schedule commitments, equipment co-ordination, and owner – contractor communications. Since coming to OBB, Marty has excelled at running a majority of our medical projects. He has elevated his status to general superintendent. Marty resides in Vacaville, California.


O’Brien Builders’ success is based on integrity, dependability, quality , and service. We hire to seek and train people with like traits. As these characteristics are upheld by each member of O’Brien Builders team, the quality of work and the realization of value will be achieved for each of our clients. Our business and work ethic will lead to a continuation of new projects. Success will be achieved by a pledge of all at O’Brien Builders to assure client satisfaction, and the confirmation to potential clients of our commitment to this philosophy.



O’Brien Builders strives to be a premier contractor emphasizing that all who we encounter in the construction industry will be treated with the upmost respect & honesty.  We will always stand by our word and be transparent in our processes & relationships.



The service provided to our clients will always be at the peak level for any contractor-owner relationship.  Our administrative staff, project managers, and owner will continually be available and in communication with our clients, subcontractors & vendors.



The work O’Brien Builders provides to our clients will never be compromised in terms of quality. We will always use the appropriate subcontractors, tradesman & vendors for the project at hand without ever sacrificing the excellence of our product for economic tradeoff.



O’Brien Builders has consistently been a contractor for their word.  They will do what it takes to make schedules happen & perform as promised to owners.  Our scheduling expertise allows for ontime project completions without uncomfortable delays.  We pride ourselves in handing over the key as promised.

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