The Building and Safety Division provides plan checking and building inspection services. The division's goal is to protect the people who live and work in the City through review of construction plans before work begins and monitoring the work through completion. The Building and Safety Division is responsible for enforcing the California Building, Plumbing, Electrical and Mechanical codes, the San Gabriel Municipal Code, and other pertinent provisions of the State, Federal and County health codes. They also retain a history of permit records for properties within the city.

Every three years, the State of California Building Standards Commission adopts new building and fire codes to regulate construction projects. These updates are done in order to implement improved life-safety standards as new scientific and technical evidence is developed.

The City of San Gabriel, along with the cities in the Los Angeles Basin, established a committee to carefully examine the new code and made a number of structural amendments due to our proximity to the seismic faults. As explained by Building Official Joseph Chen, "These amendments are essential to help maintain the structural integrity of low-rise projects in our seismic zone, as many of the minor residential additions and alterations are designed prescriptively without benefiting from the expertise of a registered professional."