(a) All housing assisted by an authority created pursuant to this division shall remain affordable for at least 55 years for rental units and 45 years for owner-occupied units.
(b) The authority shall execute an enforceable and verifiable agreement with a public agency, a recorded deed restriction, or other legal document that restricts the project’s usage and that provides that the units designated for use by lower income households are continuously available to or occupied by lower income households at rents that do not exceed those prescribed by Section 50053 of the Health and Safety Code, or, to the extent that the terms of federal, state, or local financing or financial assistance conflicts with Section 50053 of the Health and Safety Code, rents that do not exceed those prescribed by the terms of the financing or financial assistance.