Kate Warner

Kate Warner received her B.A. in Government and Communications/Rhetoric in 1980 from CSUS. After graduating with honors from Hastings College of Law three years later, she co-founded the Environmental Law Society and clerked for the 9th Circuit U.S. Court of Appeals, winning the American Bar Association’s Land Use Award. She then joined Carroll, Burdick, and McDonough as a defense litigator, practicing extensively before numerous state and federal agencies, as well as in State and Federal Courts.

After the defense of municipalities and engineering firms from claims arising from the catastrophic Bay Area landslides of 1982, Kate realized her passion lay in the science of building and related claims. As a result, Kate moved her practice to Marin County in 1988 with the firm of Hoskins & Ropers, where, mentored by John Rosenberg, she merged her affinity for the built and physical world with construction law as a specialty.

In 1991, Kate opened her own office, representing private, business and entity clients and, in litigation, representing both plaintiffs and defendants, with an emphasis on Construction. In 1996, she made the decision to focus the firm exclusively on Construction, growing the team to include Gerald Carroll, Lori Kidd, and Kelly Sperry. The firm became Kate Warner Construction Lawyers (KWCL) in 2016.

Kate’s “free time” is usually spent testing the limits of gravity, hydrology and tetanus shots.

Memberships, listings, and organizations

  • AGC (Associated General Contractors of California)
  • Bar Association of San Francisco
  • California State Bar Association
  • Construction Dispute Resolution Boards of America (Certified Panelist Member)
  • CSI (Construction Specifier’s Institute), Redwood and San Francisco Chapters
  • DRI (Defense Research Institute)
  • Marin Builders Association
  • Marin County Bar Association
  • Marin Trial Lawyers Association
  • National Association of Women in Construction
  • National Cannabis Industrial Association (NCIA)
  • WestCon (Western Construction Forensic Consultants Association)
  • (And just about every Horticultural Society in Northern California)


  • California Supreme Court (and all state courts in California)
  • United States District Court, Northern District of California
  • United States District Court, Eastern District of California