Potable water consumption needs to be reduced, meters help in determining the usage and set the limits for the owners and the tenants.
CALGreen Code Section 5.303.1: Meters.
Separate submeters or metering devices shall be installed for the uses described in Sections 5.303.1.1 and 5.303.1.2.
CALGreen Code Section 5.303.1.1: New buildings or additions in excess of 50,000 square feet.
Separate submeters shall be installed as follows:
1. For each individual leased, rented, or other tenant space within the building projected to consume more than 100 gal/day (380 L/day), including, but not limited to, spaces used for laundry or cleaners, restaurant or food service, medical or dental office, laboratory, or beauty salon or barber shop.
2. Where separate submeters for individual building tenants are unfeasible, for water supplied to the following subsystems:
a. Makeup water for cooling towers where flow through is greater than 500 gpm (30 L/s).
b. Makeup water for evaporative coolers greater than 6 gpm (0.04 L/s).
c. Steam and hot-water boilers with energy input more than 500,000 Btu/h (147 kW).
CALGreen Code Section 5.303.1.2: Excess consumption.
A separate submeter or metering device shall be provided for any tenant within a new building or within an addition that is projected to consume more than 1,000 gal/ day.
The intent of this code requirement is to reduce potable water use in new or altered buildings by making building owners and/or tenants aware of their daily potable water consumption to encourage voluntary reduction. When the meters are installed, the building operator will have the ability to establish a water consumption baseline to monitor future water use. This will give the building operator the ability to isolate and identify areas within the potable water system that have significant increases in water use due to leaks, overuse, etc.
Note: This requirement is not intended to serve as an owners’ tool for water usage billing.
For CALGreen Code Section 5.303.1.1:
1. Determine if the new project is in excess of 50,000 square feet; or
2. If an addition, determine if it is in excess of 50,000 square feet.
If the project meets one of the above-mentioned criteria, then:
3. Determine if leased, rented or other tenant space within the 50,000-square-foot building (including spaces used for laundry or cleaners, restaurant or food service, medical or dental office, laboratory, or beauty salon or barber shop) is projected to consume more than 100 gallons per day. If applicable, indicate on the construction documents the location of the separate submeters to be installed.
Note: There are exceptions in Section 5.303.1.1, Item 2 for make up water for cooling towers, evaporative coolers, and steam and hot water boilers.
For CALGreen Code Section 5.303.1.2:
- Determine if a tenant is projected to consume more than 1,000 gallons per day, and then provide a separate submeter or metering devices. Examples are car washes and aquariums.
Show separate meters on the plans (Site Utility Plan) and provide specifications for the submeters and/or metering devices.
Plan intake: The plan reviewer should confirm on the plans and specifications that separate meters and/or metering devices are specified when required.
On-site enforcement: The inspector should verify that all separate submeters and/or metering devices are installed in accordance with the approved construction documents.
(Excerpted from ‘Guide to the 2019 California Green Building Standards Code Nonresidential’ – Chapter 5)