Only with a recorded easement, and often only as an exception. Phoenix expects each building site to tie directly into city service and allows a private line across a lot line only with Water Services approval, a recorded private utility easement and a maintenance agreement. Gilbert bars gas piping on another lot unless a legal easement exists.
What is the starting rule?
Each lot should connect on its own. Phoenix's policy is written plainly: "City Code and the building code requires that all building sites tie directly into city services without routing domestic sewer, water and fire lines across interior property lines or parcels. If a lot does not already have public services, the developer shall extend public water/sewer to each lot and initiate plans for main extensions."
The Phoenix amendment to the building code's Chapter 1 says it more bluntly: "No sewer service, water service, or electric wiring methods and equipment shall be built across a lot line, other than a lot line separating the lot being serviced from the adjacent public way." The exception is a service "located within a permanent, non-revocable private utility easement duly-recorded in the deed records of Maricopa County for all the properties involved," which the building official may approve (Section 104.10.3.1).
The city adds that "It is the developer's burden to document why this might be technically infeasible, not financially expensive." Cost alone does not justify crossing a lot.
Queen Creek's subdivision ordinance says something similar for sewer: "Every developable lot shall have a separate sewer service lateral, except those lots on an approved septic system." It also requires that "Easements will be required for all private utilities outside of the street right-of-way."
When is a private line across a neighbor's lot allowed?
In Phoenix, only when public service is not available at the parcel and the city agrees. The packet explains that "private utility easements, private maintenance agreements, and City of Phoenix approval" through a "Private Utility Crossing Property Line packet" "may be considered as an alternate solution." The application "shall identify why the site(s) affected are not able to provide independent public services to each individual lot."
Gas has its own rule. Gilbert's amendment to the fuel gas code says "No gas piping system shall be located in any lot other than the lot which is the site of the building or structure served by the gas piping system. Exception: Gas piping systems may cross property lines within legally established easements." That text comes from the 2020 edition of Gilbert's technical codes, so confirm the current edition with the town before relying on it. Other cities may adopt the model code without that amendment, so check yours. Gas piping is a safety item, and a licensed contractor and the local permit office should be involved in any design.
What does the paperwork look like?
Phoenix publishes a template, which shows what a sound private easement includes. It describes a "perpetual, non-exclusive easement" for a private water, sewer or fire line, granted by the owner crossed (the grantor) to the owner served (the grantee), and says the easement "shall run with the land." The steps in the city's instructions:
- 1Get Water Services approval first, through a Water Department technical appeal.
- 2Prepare the easement agreement. Grantors and grantees sign and notarize it.
- 3Attach sealed exhibits. Each exhibit must be "sealed by an Arizona licensed civil engineer or surveyor," with a drawing of the parcels, assessor parcel numbers and a legal description.
- 4Create a maintenance agreement between the affected owners for the private line.
- 5Record both documents with the Maricopa County Recorder.
- 6Give the city the recorded copies so they attach to the construction drawings.
Phoenix's building code adds that such agreements "shall be in writing, shall be approved by the building official and shall be recorded in the deed records of Maricopa County for all the properties involved," and that the building official can revoke an agreement for noncompliance.
The packet also says the easement "shall not be amended or abandoned unless the City of Phoenix Building Official certifies that all buildings have been made to fully comply with the applicable provision of the Phoenix Construction Code without need for this easement." In other words, you cannot simply cancel it later.
Recording matters for another reason. A.R.S. 33-411 says an unrecorded instrument affecting real property does not give notice of its contents to later purchasers. The next owner of either parcel needs to be bound.
What if the neighbor says no?
Then you do not have an easement. Cornell's Legal Information Institute notes that easements can be created "by an express grant, by implication, by necessity, and by adverse possession," but the last three rest on legal claims, and they are not something to plan a project around. A line that crosses a lot without permission is a trespass and a likely violation of the permit. If you cannot get consent, the practical path is to extend public service to your own lot. Our page on who pays to extend a water or sewer main to a new commercial building walks through that.
Questions to settle before you ask
- Who maintains the line, and who pays for repairs? See two commercial parcels sharing a sewer line.
- Where exactly will the strip run, and does it conflict with existing easements? See how to find the utility easements on your commercial property.
- What if the line crosses an existing public utility easement? See whether a plumber needs permission to work inside a utility easement.
- Does the lender or title company need to approve it? Often yes, and an attorney can advise.
HQ Plumbing & Air gives free estimates and upfront pricing on commercial sewer and water line work, and can camera the existing lines to show what you are tying into.
This page explains general rules and is not legal advice. The recorded easement, your city's current policy and an attorney's review control.