If you plan to make physical improvements to the outside of your existing business, you may need to secure design review approval and/or permits first. Contact the Planning Division for the level of design review that may be required.
Also contact the Building Division to determine if a Building Permit is required for the exterior improvements.
Interior Building Improvements
If you plan to make physical improvements to the inside of your existing business (e.g. add partition walls, restrooms, electrical connection, etc), you may need to secure a permit 1st. Contact the Public Works Department for applicable Impact Fees. Depending on the extent of the proposed improvements, approvals from outside agencies such as Santa Clara County Fire Department and South County Regional Wastewater Authority (SCRWA) Pretreatment Program may also be required.