Accessory Dwelling Units (ADUs) are attached or detached accessory dwellings that are accessory to primary Residential Facilities located on the same lot… Below you will find information about the services we offer and addresses to our Oakland and Tri-Valley office locations.City of Oakland Business Tax Office 250 Frank H. Ogawa Plaza, Suite 1320. The City of Oakland Park is celebrating its commitment to sustainability and 27years as a certified National Wildlife Federation Community. College is your time to take chances, develop relationships and explore possibilities.