What sets the meter size and capacity fee for a commercial building?

By counting water supply fixture units from the plumbing plans, then converting to gallons per minute. Phoenix's commercial worksheet has the applicant total the new and existing fixture units from the 2024 UPC or IPC tables, note whether the system is mostly flush tank or flush valve, convert the total to a demand in gpm, and add other use such as landscape irrigation, cooling towers and process equipment. It then walks through the pressure math: pressure at the tap, meter loss, losses from special equipment such as a backflow preventer, filter or softener, and the drop from any elevation difference.

Phoenix's meter guideline then assigns each meter size a maximum flow and a fixture unit limit. If a design goes over the listed values, it must go up to the next larger meter.

The guideline's other columns split the fixture unit limits by whether the toilets and urinals are flush tank or flush valve, and the flush valve limits are far lower. For a 1-inch meter the table allows 127 to 129 fixture units for flush tank systems and 48 to 50 for flush valve systems. A restaurant or office with mostly flush valve fixtures reaches the limit much sooner than the same count of tank toilets. Phoenix’s guideline includes a comparison of fire-flow and fixture-unit sizing, but that does not authorize combining commercial demands. Its separate-connection requirement and limited single-family fire/domestic exception must also be followed.

### What other rules shape the meter?

• One demand, one connection. Combination fire, domestic and landscape meters are prohibited in Phoenix, with an exception for single-family lots. Each demand needs its own service connection.
• Irrigation. A separate landscape tap and meter is required for irrigated areas over 10,000 square feet or 1,000 gallons per day.
• Minimum tap. New service taps for buildings are at least 1 inch. Three-quarter inch taps are for landscape irrigation or other approved special uses.
• Master meters. One service line and master meter can serve several buildings on the same lot or an apartment project. Where an uninterrupted supply matters, the guideline describes separate metered connections and manifolding. Have Water Services confirm the permitted arrangement for the project.
• Large meters. Meters of 6 inches and up need advance consultation with Water Services on availability, cost and delivery schedule.
• The main matters. A new service connection is limited to 50 percent of the service main's diameter.
• Other utilities. Arizona Water Company points you to the fixture count section of its service request form to find the meter size.

Cities use different names. Phoenix charges impact fees, water resource acquisition fees and development occupational fees. Impact fees pay for the infrastructure needed to accommodate new development. Water resource fees cover the water supplies for it and are calculated by meter size and location. Occupational fees defray costs to the water and wastewater systems when new buildings, additions and remodels need a new meter or a larger one.

Phoenix's guideline says these fees "vary by area and are based on the water meter size, not the tap size." Commercial and industrial occupational fees are calculated by meter size and type (disk, compound or turbo), and by whether the site is inside or outside city limits. Residential fees are flat by type of use. The water and sewer occupational fees are the same amount, added together for the total. Inside Phoenix, the Planning and Development Department collects them before the building permit is issued. For sites outside the city, Water Services collects them before connection.

Scottsdale uses the same logic. Its sewer tap page says properties requesting new sewer service pay Sewer Development Fees based on meter size. Mesa calls it a capacity fee. Its code says new customers bear a proportionate share of adding capacity to the water and wastewater systems, and that the city assesses water and wastewater capacity fees for new or upsized water connections by meter size. A building permit holder pays it when requesting a connection.

### Does a remodel trigger it?

It can. Phoenix says its occupational fees apply when new buildings, additions and remodels require new meters or an increase in meter size. A tenant improvement that adds fixtures can push you into a bigger meter, and the fee follows. Our page on commercial tenant improvement plumbing covers the plumbing side of that project.

The rules above turn into different answers for different buildings, and the difference is worth seeing before you commit to a size.

• A restaurant with flush valve restrooms and a full kitchen. The flush valve limit governs, and the kitchen adds fixtures for dishwashers, prep sinks and hand sinks. This is the type of site where the fixture count, not the floor area, decides the meter.
• An office building with tank toilets and a landscaped frontage. Domestic fixtures may fit a smaller meter. The landscaping is a separate matter: once the irrigated area passes the 10,000 square foot or 1,000 gallon threshold, it needs its own tap and meter rather than a bigger domestic meter.
• A building with a fire line. Fire demand is its own connection in Phoenix. Do not size the domestic meter to cover it, and do not try to combine them.
• A shopping center pad with a master meter. Where several buildings share one lot, master-meter and continuity requirements affect the arrangement; ask Water Services to confirm the permitted connections.

Two habits keep the number honest. First, have the plumbing designer produce the fixture unit count that the utility's worksheet asks for, and keep it with the plans. Second, ask the utility what happens if the count changes during design. Phoenix's fee is tied to the meter installed, so a late change in the restroom count can move you to a different size and a different fee.

• What size and type of meter does my fixture count and demand require?
• Are my fees based on meter size, and which fee schedule applies at my location?
• Is a separate irrigation meter required for the landscaping?
• Who installs the meter, and when are fees due: before the building permit, or before connection?
• What is the process to change the meter size later if the use changes?

Size the meter from the plumbing plans, not from a guess or a neighbor's building. Count fixtures accurately and keep irrigation and fire on their own connections, as the rules require. Then ask the city for a fee estimate before final plans. Phoenix directs fee questions to its Impact Fee Team and fee schedules change, so this page gives no dollar figures. Get the current schedule from your utility.

The meter comes after the utility says it can serve you and before the tap. See will-serve letters, how a tap works and what offsite plumbing is.

For water needed during construction, compare the separate temporary hydrant-meter process with the permanent service plan.

For the piping on your side of the meter, HQ Plumbing & Air gives free estimates and quotes the price up front.