Information needed to complete each form section. Any deadlines associated with each form filling timeline if a deadline exists.Welcome to the homestead estimated amount page for Single Family Detached homes for Contra Costa county. You generally need to apply for the exemption only once, and the deadline for applications is usually April 10th each year. Exemption forms are due June 30th each year. Once forms are filed exemption is automatically renewed each year. If you're not signed up, expect to file a onepage application. Select all exemption(s) for which you are applying: Basic Homestead Exemption. The new California Homestead Exemption was introduced through AB 1885 on Sept 18, 2020. The legislation will take effective on Jan 1, 2021.