​Note

In San Jose, if you plan to build a backyard office, you generally need a building permit if the structure exceeds 120 square feet. For smaller structures, permits might still be required depending on various factors such as the inclusion of electrical, plumbing, or HVAC systems. Here are key points to consider:

1. Size and Use: Structures over 120 square feet usually require a permit.

2. Setbacks: Must adhere to distance requirements from property lines and other structures.

3. Utilities: Adding electrical or plumbing requires additional permits.

For more detailed and specific information, you can visit the City of San José Building Permits page.