San Francisco’s Most Trusted Mechanical Contractor for More Than 100 Years.

From new construction and tenant improvements to long-term mechanical maintenance, AR&B delivers the technical expertise, safety discipline, and execution required by the Bay Area’s most complex commercial facilities.

Group of construction workers wearing safety gear and helmets standing inside a building under construction, with large windows and cityscape visible in the background, holding a certificate or award.

AR&B brings HVAC, plumbing, and fire protection together under one roof, with its headquarters and fabrication operations in San Francisco.

Three Mechanical Trades

Man in safety vest and helmet holding an award certificate on a construction site with city buildings and bridge in background.

HVAC

San Francisco buildings demand HVAC systems engineered for complexity, efficiency, and long-term reliability. For decades, AR&B has fabricated and installed mechanical systems locally, helping buildings perform efficiently and reliably under the Bay Area’s demanding operating conditions and constantly changing microclimates.

Man in construction attire holding an award plaque at a construction site with metal framing, a red ladder, and construction tools and equipment around him.

Plumbing

San Francisco’s aging infrastructure, seismic requirements, coastal corrosion, strict municipal standards, and densely occupied commercial buildings create unusually complex plumbing challenges. AR&B builds durable systems designed to perform for decades, with the technical precision, safety discipline, and proven craftsmanship critical infrastructure demands.

Three young men standing in front of a large shelf filled with metal pipes and equipment in a workshop or warehouse. One man holds a plaque or certificate. They are smiling and dressed in casual work attire.

Fire Protection

AR&B designs and installs fire protection systems built to meet strict code requirements, pass critical inspections, and protect critical facilities through precise execution and proven craftsmanship. Beyond installation, AR&B partners with building owners and facility teams to support ongoing compliance with NFPA 25 inspection, testing, and maintenance requirements.

For more than 105 years, AR&B has supported complex commercial construction projects throughout San Francisco and the Bay Area across HVAC, Plumbing, and Fire Protection systems. AR&B has helped build the mechanical infrastructure that defines San Francisco’s commercial landscape. Headquartered in San Francisco with in-house fabrication and all three mechanical trades operating under one roof, AR&B delivers the coordination, safety, and technical knowledge required to meet the demanding schedules and complex requirements of modern construction projects.

105 Years & Growing

A group of construction workers and managers wearing helmets and safety vests standing inside a building under construction with exposed framework, ductwork, and construction equipment.

Routine Maintenance for Mechanical Systems

AR&B has helped Bay Area facilities keep critical building systems operating safely, reliably, and without interruption. Backed by more than 170 highly skilled employees, specialized expertise across HVAC, Plumbing, and Fire Protection, a long-tenured workforce, an exceptional Experience Modification Rate (EMR) of 0.53, and in-house fabrication capabilities in San Francisco, AR&B delivers the rapid response and technical depth needed to support the systems businesses rely on every day. Learn more about AR&B’s routine maintenance services.

Learn More
Four construction workers in black safety jackets and helmets with high visibility strips, standing inside a building under construction with large windows showing a city skyline in the background.

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Speed. Quality. Craftsmanship From fabrication floor to delivery truck, this is what happens when sheet metal is built by people who know how it needs to perform in the field. Made in San Francisco. Built for installation. Built to last. #SheetMe
Speed. Quality. Craftsmanship From fabrication floor to delivery truck, this is what happens when sheet metal is built by people who know how it needs to perform in the field. Made in San Francisco. Built for installation. Built to last. #SheetMetal #HVAC #SanFrancisco #MechanicalConstruction #ARBMechanical
This is what a drawing looks like when it becomes a reality at the hands of #arbmechanical’s amazing sheet metal fabricator Gabe Gamez On paper, it’s lines, dimensions, dampers, sensors and controls. In our San Francisco fabrication sho
This is what a drawing looks like when it becomes a reality at the hands of #arbmechanical’s amazing sheet metal fabricator Gabe Gamez On paper, it’s lines, dimensions, dampers, sensors and controls. In our San Francisco fabrication shop, it becomes this. These mixing boxes are being built to take hot and cold air, precisely control the mixture, and deliver the temperature and airflow the space needs. The concept is straightforward. Getting every dimension, transition, damper and connection right — and building it so it fits and performs in the field — is where the craft comes in. From drawing. To fabrication. To the building. That’s mechanical construction. #HVAC #SheetMetal #MechanicalConstruction #Fabrication
Creative solutions for challenging problems. The very best of the best. #arbmechanical. #hvac #plumbing #fireprotection #sheedycrane
Creative solutions for challenging problems. The very best of the best. #arbmechanical. #hvac #plumbing #fireprotection #sheedycrane
Successful projects begin long before construction starts. #ARBmechanical partners with owners, architects, engineers, and general contractors early in the process to develop mechanical systems that are practical to build, efficient to operate, and d
Successful projects begin long before construction starts. #ARBmechanical partners with owners, architects, engineers, and general contractors early in the process to develop mechanical systems that are practical to build, efficient to operate, and designed for the realities of building in San Francisco and throughout the Bay Area. #hvac #plumbing #fireprotection #designbuild
Another successful morning with @sheedycrane at 1650 Mission St., removing the old tower and landing the new one. We are working on the #piping connections now. @sheedycrane #arbmechanical #hvac #fireprotection #weekendwork
Another successful morning with @sheedycrane at 1650 Mission St., removing the old tower and landing the new one. We are working on the #piping connections now. @sheedycrane #arbmechanical #hvac #fireprotection #weekendwork
@gallagherglobal Interns getting a full mechanical walk through of a @novoconstruction and #arbmechanical on a 5 floor private client project. Special thanks to Tyler, Terry, Rich, and Fernando for hosting. #hvac #plumbing #fireprotection #safety
@gallagherglobal Interns getting a full mechanical walk through of a @novoconstruction and #arbmechanical on a 5 floor private client project. Special thanks to Tyler, Terry, Rich, and Fernando for hosting. #hvac #plumbing #fireprotection #safety
We are so proud to have such cool neighbors in the #SFDogpatch. Aruna and her team from @VolcanoKimchi stopped by with a selection of fermented treats for the AR&B team. We tried—and loved—the #MangoKimchi, along with her all-star li
We are so proud to have such cool neighbors in the #SFDogpatch. Aruna and her team from @VolcanoKimchi stopped by with a selection of fermented treats for the AR&B team. We tried—and loved—the #MangoKimchi, along with her all-star lineup of #NapaKimchi, #SmokeShowKimchi, and the red-cabbage-based #NakedAndFamousKimchi. Her jicama and bok choy kimchi disappeared faster than a box of donuts on a Monday morning. It was a fun afternoon for the team, and we all learned a little more about the art and science of fermentation. Thank you, Aruna and the Volcano Kimchi team, for stopping by!
A special thanks to @cooperrmatthies (left), Project Engineer, and Darragh Mulhern (right), Engineering and Design interns, for #arbmechanical. You were a huge help and made the summer months both more productive and fun. We appreciate all of your ha
A special thanks to @cooperrmatthies (left), Project Engineer, and Darragh Mulhern (right), Engineering and Design interns, for #arbmechanical. You were a huge help and made the summer months both more productive and fun. We appreciate all of your hard work and the positive impact you made. #nationalinternday #arbmechanical #thefuturelooksbright
Safety is about more than preventing falls, wearing the right PPE, or following procedures on a jobsite. It is also about being prepared when someone’s health suddenly depends on the people around them. The AR&B team completed hands-on CP
Safety is about more than preventing falls, wearing the right PPE, or following procedures on a jobsite. It is also about being prepared when someone’s health suddenly depends on the people around them. The AR&B team completed hands-on CPR training—learning skills that can protect our coworkers in the office, our teams in the field, and the people waiting for us at home. CPR is serious work, but the training comes with one memorable instruction: perform chest compressions to the rhythm of the Bee Gees’ “Stayin’ Alive.” It may be the only safety training where getting a song stuck in your head is considered a successful outcome. At AR&B, safety does not stop at the edge of the jobsite. It means building the awareness, confidence, and practical skills to take care of one another wherever we are. Because everyone deserves the best chance to keep stayin’ alive. #ARBMechanical #SafetyFirst #CPRTraining #WorkplaceSafety #ConstructionSafety
The AR&B Mechanical HVAC and Plumbing Teams are crushing it at Coinbase—delivering on time, on budget, and to the highest standards of quality and safety. That’s how we get it done, every time. #ARBMechanical #HVAC #Plumbing #FirePr
The AR&B Mechanical HVAC and Plumbing Teams are crushing it at Coinbase—delivering on time, on budget, and to the highest standards of quality and safety. That’s how we get it done, every time. #ARBMechanical #HVAC #Plumbing #FireProtection #SMACNA #mechanicalcontractor
Speed. Quality. Craftsmanship From fabrication floor to delivery truck, this is what happens when sheet metal is built by people who know how it needs to perform in the field. Made in San Francisco. Built for installation. Built to last. #SheetMe This is what a drawing looks like when it becomes a reality at the hands of #arbmechanical’s amazing sheet metal fabricator Gabe Gamez On paper, it’s lines, dimensions, dampers, sensors and controls. In our San Francisco fabrication sho Creative solutions for challenging problems. The very best of the best. #arbmechanical. #hvac #plumbing #fireprotection #sheedycrane Successful projects begin long before construction starts. #ARBmechanical partners with owners, architects, engineers, and general contractors early in the process to develop mechanical systems that are practical to build, efficient to operate, and d Another successful morning with @sheedycrane at 1650 Mission St., removing the old tower and landing the new one. We are working on the #piping connections now. @sheedycrane #arbmechanical #hvac #fireprotection #weekendwork @gallagherglobal Interns getting a full mechanical walk through of a @novoconstruction and #arbmechanical on a 5 floor private client project. Special thanks to Tyler, Terry, Rich, and Fernando for hosting. #hvac #plumbing #fireprotection #safety We are so proud to have such cool neighbors in the #SFDogpatch. Aruna and her team from @VolcanoKimchi stopped by with a selection of fermented treats for the AR&B team. We tried—and loved—the #MangoKimchi, along with her all-star li A special thanks to @cooperrmatthies (left), Project Engineer, and Darragh Mulhern (right), Engineering and Design interns, for #arbmechanical. You were a huge help and made the summer months both more productive and fun. We appreciate all of your ha Safety is about more than preventing falls, wearing the right PPE, or following procedures on a jobsite. It is also about being prepared when someone’s health suddenly depends on the people around them. The AR&B team completed hands-on CP The AR&B Mechanical HVAC and Plumbing Teams are crushing it at Coinbase—delivering on time, on budget, and to the highest standards of quality and safety. That’s how we get it done, every time. #ARBMechanical #HVAC #Plumbing #FirePr