This form is intended for use with the. Official Forms for Viewing and Downloading.This Addendum is intended for use in the City of San Pablo. Please also review the separate Contra. Edit, sign, and share contra costa purchase agreement addendum online. No need to install software, just go to DocHub, and sign up instantly and for free. The cost to County of completing Contractor's performance shall be deducted from any sum due Contractor under this Contract, without prejudice to County's. How to fill out the California Residential Purchase Agreement and Instructions? The following is a list of some documents that may be recorded if they meet all requirements, and a description or definition of each document.