About Us
About the company
AGC is able to consistently deliver customer service because we have engineers and project managers that know how to ask questions and know how to listen. When we begin each project, we engage with the customer to communicate the project goals and constraints. Throughout the design and construction process, we look out for the customer's interest by initiating discussion about design issues early and often to minimize change costs and schedule impacts. We do not sit back and wait for the customer to ask for help. We actively look for ways to assist both the customer and the project team to achieve mutual success.
For AGC, customer service sometimes means offering solutions to unique problems that the typical mechanical contractor would consider outside their scope of work. For instance, we developed a complete testing and documentation program for fire/smoke dampers to help hospitals meet JHACO maintenance requirements. And, on several occasions, we have evaluated sound and vibration problems in existing buildings, recommended solutions, and implemented the solutions in the field.
AGC's track record of customer service is proven by the long-term relationships that have been developed with both owners and general contractors. We would love for you to join our growing network of satisfied customers.
Our Philosophy
AGC believes in customer service. Our customers rely on us to bring our professional expertise, our commitment to quality, and our industry experience to each and every project. - Any mechanical contractor can install piping, secure an air handler, or start up a pump. But true expertise lies in the dedication to long-term customer success. At AGC, we go beyond the basics—delivering reliability, industry-leading expertise, and lasting value in every project.
Meet the Team
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Randy Attaway
Vice President
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Beth Guinnane
CFO
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Jun Yamaguchi
Project Manager / Owner
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Jon Mohs
President and CEO
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Renee Hazel
Controller
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Keith Anderson
Piping Superintendent
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Danny Martinez
Sheetmetal Superintendent
Meet Our Project Manager
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Garry Baughman
A third-generation industry professional with over four decades of experience, Garry brings deep expertise in sheet metal and construction, backed by five years at AGC. With a foundation in hands-on training and a lifetime immersed in the trade, he consistently delivers strong project leadership and practical insight to every job.
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Steve Flores
With 32 years in the mechanical and plumbing industry—from apprentice to AGC’s Preconstruction Manager—Steve brings deep, hands-on experience backed by a Mechanical Engineering degree from San Jose State and journeyman training from JATC Local 393.
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Scott Stalie
A fourth-generation plumber with over 30 years of experience in plumbing, mechanical, and wet utilities, Scott brings deep technical knowledge and field expertise to AGC. After decades of business ownership and specialized certifications, he joined AGC in 2023 as a Project Manager, continuing a legacy of excellence and hands-on leadership
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Rich Guinnane
With over 30 years in the industry and 24 years at AGC, Rich brings a wealth of hands-on experience leading projects of all sizes. Backed by certifications in med gas, OSHA 30, and confined space safety, he combines deep field knowledge with personable leadership and strong problem-solving skills
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Bill Schoening
With over 15 years at AGC Inc., Bill brings a strong foundation in mechanical engineering and project management, specializing in healthcare and public works. A licensed Professional Engineer and Safety Director since 2017, Bill is known for critical thinking, leadership, and professionalism under pressure.
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Matthew Herrera
Matthew brings fresh energy to the industry, gaining hands-on experience alongside veteran project managers at AGC. With a growing foundation in project delivery and a strong team presence, he is quickly emerging as a valuable contributor to the success of complex projects.
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Diana Jarvio-Musante
With a background in office management and a BA from UCSC, Diana brings a collaborative and client-focused approach to every project. Passionate about learning from the field and supporting her team, she’s building a strong foundation in project delivery at AGC.
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Russ Maurice
With over 36 years in construction and manufacturing, Russ has spent the past eight years managing complex mechanical projects across education, healthcare, and semiconductor sectors. A certified project manager and five-year AGC team member, he leads with experience, empathy, and a belief in empowering teams to succeed together
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Max Arana
With over 17 years in the HVAC, mechanical, and plumbing industry, Max brings deep field and project experience to AGC as an Estimator/Project Manager. Having worked on high-density high-rise developments and collaborated closely with GCs to meet critical deadlines, he continues to deliver precision and reliability to every project since joining AGC in 2024
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Vic Galvez
With 25 years in union commercial plumbing—including leadership roles in TI, education, lab, and government projects Vic brings field-tested expertise and sharp project management skills to AGC. Backed by advanced trade training and a strong focus on communication, responsiveness, and problem-solving, he joined AGC in 2025 drawn to its structured, team-driven culture.
Our History
AGC, Inc was founded at the end of 2000 by the current principals, Randy Attaway, Beth Guinnane, Tony Volpi, and Jon Mohs. Bringing together their combined experience in commercial and industrial HVAC, process piping, cleanrooms, labs, biotech facilities, and hospitals. We were experienced in engineering/design, estimating, project management, field supervision, permitting, and project closeout. We believed that we could provide a level of service and experience to the industry that was rare for a small startup mechanical contractor.
Since that time, we have steadily grown as a company and have proven that indeed we do provide the high level of service that is required by today's clients and general contractors. We have worked on many projects, small and large and have repeatedly delivered professional, on-schedule, and in-budget results. This, we believe, is the result of our commitment to meeting and exceeding customer expectations.
We understand that we cannot be successful unless our clients are successful. So, we work hard to uncover project issues early and offer well-informed, budget-conscious solutions. We work hard to maintain excellent relationships with our material and equipment suppliers so that we can get work done quickly and efficiently. And, we work hard to develop wide-open communication lines with our clients to maximize alignment with project goals and accelerate feedback from the rest of the project team.
Mission Statement
- Building environments that nurture innovation, learning, and well-being across education, research, technology, and healthcare.
AGC Team.