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Based in San Diego, Countywide Mechanical Systems is dedicated to providing the highest level of service to its clients. The company specializes in construction, preconstruction, and service of commercial HVACR and plumbing projects for their valued clients in healthcare, high-rise, government, and more.

Our Clients Come First

At Countywide Mechanical Systems, we want to deliver an unparalleled construction experience to our clients. Therefore, we continually strive to provide innovative solutions to each and every one of our partners.

Our Values Lead the Way

Ever since our founding, we’ve been driven by our values of integrity, quality craftsmanship, teamwork, and entrepreneurial spirit to build partnerships that last.



Integrity is our cornerstone. By conducting our business according to the highest standards of integrity and ethical behavior, we always tell the truth, keep our promises, and hold ourselves accountable for every decision we make.

We embrace teamwork while respecting the individual. Our foundation of teamwork and collaboration allows us to build sustainable relationships with our fellow employees, our clients, our business partners, and our communities.

We believe in the power of our entrepreneurial spirit. Our success comes from having the imagination to visualize what is possible, the courage to try new things, and the resourcefulness to always find a way to get it done.

We take pride in our craft, ensuring quality, safety, and value on every job. It’s critical that every aspect of our work reflects the highest level of quality, safety, craftsmanship, and professionalism.

Our Success is Your Success

As part of the MMC Corp family of companies, we are 100% employee owned, meaning we don’t see success until our clients do. With a stake in the success of each and every project, our employee owners take pride in a job well done and pull for each other in everything we do.

Check out some of the great work our employee owners have done by visiting our projects page.