Gannon Construction Company Team - Collin Gannon, Brian Gannon, Gretchen Stagg
Gannon Construction Logo

Our Core Values

Honesty | High Quality | Customer Focus
Efficiency | Build Economically

About Gannon Construction

Collin + Brian Gannon, Project Managers at Gannon Construction Company

Gannon Construction Company is a turnkey, full-service general contractor with a history of project success and customer satisfaction. Whether you are looking to build your dream home, remodel your restaurant, build a retaining wall, or are looking for construction consulting – we do it all.

For the past 20+ years, Gannon Construction Company has been serving clients in Marin, Sonoma, Napa, and San Francisco counties. As a family-owned and operated business, we place an emphasis on relationships and trust. We will work with you from the initial stages of a project to bring your ideas to life.

At GCC we are focused on providing the highest value to our clients. By managing all of our projects through our cloud-based project management software (Procore) and using our advanced estimating and scheduling programs, we are able to eliminate waste and expedite your project. Our use of cutting-edge technology, paired with our years of experience in the construction industry, sets us above our competition.

Gannon Construction Company is a Marin Builders Association Member and a North Coast Builders Exchange Member


General Contractor’s License #544989, Class A & B

Our Story

Before starting Gannon Construction Company, Brian Gannon worked for over 25 years as a superintendent, lead estimator, and project manager for a large commercial construction company in the Bay Area. His projects included a 200 unit condo conversion project in Cupertino; a 67 unit upper-end condo project in Marin County from raw land through buyers’ move-in; the subdivision of a 100-acre site on the American River into buildable lots including roads, utilities, and the construction of a 5,000 sf model home; The construction of 45 semi-custom homes in Mill Valley; Numerous public works projects, e.g., welded-steel water tanks for MMWD, construction of parking lots, the installation of modular classrooms, Placement of potable water lines, etc. These projects ranged from $500,000 to $20,000,000 in size.

Brian founded Gannon Construction Company in 1999 to bring to the market a General Contracting firm based on delivering high-quality work, honestly, and efficiently with a focus on customer satisfaction.

Brian Gannon – Founder + Project Manager, Gannon Construction Company at his desk with plans

Our Team

Brian Gannon – Founder + Project Manager, Gannon Construction Company

Brian Gannon

Founder and Project Manager

Brian graduated from the Dominican University of California and began his career building and selling houseboats in Sausalito, CA. Over time Brian worked his way up to the position of project manager for TRI Development, a large Bay Area commercial construction firm. As a project manager, Brian was responsible for managing all aspects of numerous construction projects. Brian’s responsibilities included contract management, selection of subcontractors and suppliers, managing employees, payroll, safety, quality control, scheduling, marketing, and sales. Today, Brian manages and oversees all GCC operations.

Jaime Trejo headshot

Jaime Trejo

Lead Foreman

Jaime has been working in the construction trades for 35 years. Before coming to work for GCC Jaime worked as a lead carpenter on a wide variety of construction projects, including large custom homes, apartment buildings, and large hotels. This experience formed Jaime into the talented and competent foreman he is today.

Gretchen Stagg – Office Manager at Gannon Construction Company

Gretchen Stagg

Office Manager

Gretchen is GCC's office manager. For 30 years she ran a private bookkeeping and tax preparation service specializing in sole proprietorships. This experience gave Gretchen a special talent for tracking money and made her a valuable member of the GCC team. Gretchen also was elected to serve on the Board of Directors for Tamalpais Community Services District.

Collin Martin – Project Manager, Gannon Construction Company

Collin Martin

Project Manager

Collin is Brian’s grandson and grew up working on his grandfather’s job sites. This early exposure to construction inspired Collin to pursue a Bachelor of Science in Construction Management from Cal Poly San Luis Obispo as well as a minor in Real Property Development. During his college summers, Collin was an intern for three different construction companies where he expanded his knowledge of the industry. Now, Collin works for GCC as a project manager splitting his time between the field and the office.