Gilbert is one of the easier Valley towns to connect a casita in, because the Town wrote its rule down in plain language: "All utility services for accessory structures must come from the primary structure's utility connections." One sewer tap per lot, one water meter per lot, and a separate electric meter if you want one. Here is how each connection works on a Gilbert lot, what we verify, and what it costs.
The short version
In Gilbert, your ADU shares the sewer and water service your home already has, and can get its own SRP or APS electric meter, which is our standard. A separate address is optional, and we request one whenever there's a separate meter.
Distance from your home's lines to the ADU is the single biggest driver of utility cost, and Gilbert's larger suburban lots make it easy to put the unit farther away than you need to. We place it to keep the runs short.
Sewer: one tap per lot
Your ADU connects to your home's existing sewer line, not to a new tap at the main. Gilbert's ADU and accessory structures guide requires utility services for accessory structures to come from the primary structure's connections, and the Town's engineering standards state that "a single tap per lot is required and permitted," with additional taps only by written request and written Town approval. Sewer is billed on your water account, so there's no separate sewer account for the unit.
What we verify at the site visit:
- Grade. Sewer flows by gravity. If the ADU sits lower than your home's line, a small ejector pump may be needed.
- Pipe size and condition. Gilbert residential taps are 4-inch. Older homes may get a camera inspection first; damaged pipe is replaced as a change order.
- Easements. Gilbert's Land Development Code bars building an ADU over a public utility easement without written consent from the utility, and water-line easements must stay clear. We check the plat before we place the unit.
- Septic lots. If your home is on septic, Maricopa County Environmental Services must approve any addition to the system. Gilbert also requires connection to sewer if a main is within 330 feet of your property line.
Water: one meter, ADU downstream
Your ADU tees off your home's water line after the existing Town meter, with its own shutoff valve. Town Code requires a meter on each lot and specifically describes a lot "with multiple buildings served by a single meter," which is exactly what an ADU is. A separate meter is only required if the lot is later split.
- Meter size check. Sizing follows the plumbing code's fixture-unit calculation at plan review. If your existing meter can't carry the house plus the ADU, an upsize is required, and Gilbert's water and wastewater connection fees apply to the added capacity. Those fees are substantial, so confirming your meter is adequate is one of the first things we do.
- Optional private submeter. Renting the unit? The Town's guide allows a private in-line submeter on the ADU's line; the Town doesn't read it, you do. Arizona's tenant-billing rules are in our separate meter vs. submeter guide.
Electric: its own meter, if you want it
Gilbert's guide answers the meter question directly: you may request a separate electric meter for an ADU, although it is not a requirement. SRP serves most of Gilbert and APS serves part, and either will set a second residential meter once the Town has permitted the unit. A separate meter is our standard because it gives the casita its own bill and adds no load to your home's panel.
- SOKO applies to SRP or APS, and the utility sets the connection point. SRP requires Distribution Design to approve the meter location before anything is installed.
- SOKO digs the trench and installs conduit to the utility's design; the utility pulls the wire and sets the meter.
- Address. Gilbert says a separate address may be requested but isn't necessarily required. We request one through Development Services whenever there's a separate meter, so the account and the mail work cleanly.
- Plan on added utility lead time. Scheduling is set by SRP or APS, not SOKO.
Option: power from your home's panel
We can instead feed the ADU from your home's electrical panel, with one shared bill, when a load calculation shows your panel has room, usually a 200-amp service. It's often a fit for family or guest use, and if you have rooftop solar it's usually the better economics. If your panel is too small, a new ADU meter is usually better value than upgrading your home's service.
What it costs in Gilbert
Utility connections are priced per linear foot of trench plus fixed connection items. Your proposal shows the measured run lengths for your site.
Standard connections
| Item | Price | Includes |
|---|---|---|
| Sewer line, ADU to home's line | $65 / LF | Trench, 4" pipe, bedding, backfill, compaction |
| Sewer tie-in + cleanout | $1,200 each | Connection to your home's line, required cleanout |
| Water line, in shared sewer trench | $20 / LF | Pipe and fittings in the same trench as sewer |
| Water line, separate trench | $35 / LF | Trench, pipe, fittings, backfill |
| Water tie-in + ADU shutoff valve | $750 | Tee after your Town meter, dedicated ADU shutoff |
| Electric trench + conduit | $40 / LF | Trench and conduit per SRP/APS design |
| New meter service + ADU panel | $6,000 | Meter base, main disconnect, ADU panel, grounding |
| Second address (for new meter) | $350 | SOKO request and coordination with the Town |
| Utility and Town fees | At cost | SRP/APS and Town of Gilbert, including the Town's ADU system development fee, passed through with no markup |
Add-ons and site conditions
| Item | Price | When it applies |
|---|---|---|
| Water submeter on ADU line | $750 | Optional, for rental billing |
| Power from home's panel instead of new meter | $3,500 + $40 / LF | Optional, if load calc allows; replaces the $6,000 meter service and $350 address |
| Sewer camera inspection | $350 | Older homes or unknown pipe condition |
| Sewer pump (ejector) | $4,500 allowance | Only if the ADU sits too low for gravity flow |
| Water meter upsize | Town fees at cost + $1,500 | Only if the fixture calculation exceeds your current meter; Town connection fees apply to the added capacity |
| Caliche, rock, or hardscape removal | Cost + 25% | Found during excavation |
Example: a 40-foot run with shared sewer and water trench, a separate 40-foot electric trench, and a new meter comes to about $13,300 before Town and utility fees.
What moves the number
- Distance. Every foot between your home's lines and the ADU is priced. We place the ADU and route trenches to keep runs short.
- Your water meter. An adequate existing meter keeps you clear of Gilbert's connection fees, which are charged by meter size and are among the highest in the Valley.
- Town fees. Gilbert charges a published per-unit system development fee for ADUs, separate from the utility connection work. It's a Town fee and passes through at cost.
- Soil and existing conditions. Caliche, old sewer pipe, or a shallow lateral add scope.
- Utility requirements. SRP or APS sets the meter location and service route, which can lengthen the electric trench.
What this pricing assumes
- Pricing applies to Town of Gilbert projects. For other cities see our posts for Phoenix, Scottsdale, Mesa, Tempe, Chandler, and unincorporated Maricopa County.
- Run lengths are measured at the site visit and confirmed on the permit site plan.
- Utility and Town fees are billed at cost, as invoiced.
- Excludes gas service, relocation of existing utilities, landscape and hardscape restoration beyond the trench, and repairs to existing home systems.
- Requirements reflect Gilbert Land Development Code Section 5.2.3, the Town's ADU guide, and utility policies as of September 2026 and may change.
We run this for you
In Gilbert the rules are clear and the fees are the thing to watch. We confirm your meter, your sewer, and your electric provider on the first site visit, so the connection line in your proposal is a real number. Building a casita in Gilbert? Check your property or call 480-660-3133.
Sources: Town of Gilbert ADU and Accessory Structures Guide (February 2025); Gilbert Land Development Code Section 5.2.3; Gilbert Public Works & Engineering Standards (January 2026); Gilbert Town Code Chapter 66 and Chapter 10; Gilbert Development Services Fee Schedule; SRP Electric Service Specifications; Maricopa County Environmental Health Code Chapter II. Town policies, utility requirements, and fees change; verify current requirements with the Town of Gilbert and your utility before making design decisions. Pricing shown is SOKO's standard connection pricing as of September 2026 and is confirmed in your written proposal.
