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Sean Marciniak

Sean R. Marciniak

(925) 746-8471


As the leader of the firm's Land Use Practice Group, Sean has specialized in land use and environmental law for more than a dozen years. He is a former newspaper reporter and investigator for the state of Texas, and combines skill sets from across disciplines to counsel landowners, developers, and public agencies on all aspects of environmental and land use matters. Having experience in both land use entitlement and litigation, he designs permitting and environmental review strategies for development projects that maximize efficiency and defensibility, while minimizing costs and delays. He also regularly appears at administrative hearings throughout California, and adopts communication strategies that address not only legalities, but common-sense considerations. 

Sean and his team have helped entitle millions of square feet of development throughout California, including affordable housing projects, wineries and vineyards, mixed-use development, regional hospitals, laboratories, pharmaceutical campuses, shopping centers, office campuses, infrastructure projects, terminal expansions, solar energy projects, and intermodal transport facilities at California’s busiest ports.

Areas of focus include counseling under the California Environmental Quality Act, the National Environmental Policy Act, planning and zoning law, the Subdivision Map Act, takings and exactions, development agreements, initiatives and referendums, Local Agency Formation Commissions, the Housing Accountability Act, natural resource permitting (including under the Endangered Species Act and Clean Water Act Sections 401 and 404), and emerging laws addressing climate change and sustainable development.

Prior to joining us, Sean was a shareholder at Miller Starr Regalia, where he helped write and edit sections of land use practice guides, including Miller & Starr, California Real Estate 4th, a 12-volume treatise on California real estate law. He began his legal career in the environmental and land use practice at an international law firm, where he edited and wrote sections of other land use treatises and practice guides used across the state. As a journalist, Sean was a crime and investigative reporter in the Texas borderlands. His articles have appeared in publications that include The Wall Street Journal, the Dallas Morning News, and the Houston Chronicle, and have merited awards from the Associated Press and Bloomberg News. As an investigator in Texas, he looked into allegations of judicial misconduct for the State Commission on Judicial Conduct.


J.D. University of California, Berkeley School of Law ( 2007 )
M.A. University of California Graduate School of Journalism ( 2004 )
B.A. Brandeis University ( 1999 )

Admissions and Courts



Land Use Practice Leader
Air Quality Practice Leader

American Bar Association

Bay Planning Coalition, Former Board Member

Contra Costa County Bar Association

Urban Land Institute

Super Lawyers, Land Use & Zoning; Environmental (2012–2017, 2023)