Can a voluntary certification create a market signal for housing quality where regulation has failed to? We're testing whether the B Corp/Fairtrade playbook translates to rental housing, borrowing the audit-and-register model and adapting it to habitability, fair terms, and tenancy practices. The experiment is a pilot badge in one market with a defined cohort of landlords, and we're documenting whether it shifts landlord applications, tenant choice, or property care or anything at all.