Some buildings have a single gas or electric meter that serves more than one rental unit. In other buildings, a tenant’s gas or electric meter may also measure gas or electricity used in a common area, such as the laundry room or the lobby. In situations like these, the landlord must disclose to you that utility meters are shared before you sign the rental agreement or lease.61 If you become a tenant, the landlord must reach an agreement with you, which must be in writing, about who will pay for the shared utilities.
Rental units in older buildings may not have separate water meters or submeters. California law does not specifically regulate how landlords bill tenants for water and sewer utilities. Ask the landlord if the rental unit that you plan to rent has its own water meter or submeter. If it does not, and if the landlord will bill you for water or sewer utilities, be sure that you understand how the landlord will calculate the amount that you will be billed.
61 Civil Code Section 1940.9, Public Utilities Code Section 739.5.