It consists of three parts: Part A: Contract Information, Part B: Body of Contract, and Part C: Tenancy Addendum. A lease addendum allows you to add an additional document to or adjust the terms of your existing rental agreement.A California lease agreement allows a landlord of residential or commercial property to write a legally binding rental contract with a tenant. No information is available for this page. All you have to do is create the document, add in the details for that particular agreement, and send it for signature. If my landlord makes changes or adds an addendum to the rental agreement after it has been signed do they have to inform me? This Housing Agreement grants a limited license to Resident to access and make personal residential use of one assigned bedroom. Utility Addendum: This addendum clarifies how utility costs are divided between the landlord and tenant. Into a lease agreement dated November 1, 1999, for the lease of water; and. Sample lease addendums are provided on this site.