Block Wall Rules in the Four Confirmed Cities
Phoenix, Chandler, Maricopa and Flagstaff each answer "depends." The condition is what matters, so read it for your city. These rules were checked October 2026 against each city's own page.
Phoenix
Phoenix requires no building permit for fences 3 feet or less, or for retaining walls 3 feet or less measured from the top of the footing, unless the wall supports a surcharge. Above that, you need a permit. The city's wording: "Fences not included in this exception, not over seven feet high, shall require a building permit demonstrating compliance with the zoning ordinance requirements and city code requirements for site drainage only."[1]
Fences over 7 feet need structural design.[1]
No fee is published for this job on the pages read. Our Phoenix permits page covers other home jobs.
Chandler
Chandler requires a permit if the wall retains earth and is over 4 feet, measured from the bottom of the footing to the top of the wall.[2] A permit is also needed if a fence is over 7 feet high or sits on a retaining wall. Otherwise, none is required.[2]
Applications go through the city's Accela portal. Fees are not published for this job.
Maricopa
Maricopa takes a different approach. Its rule reads: "All fences/walls under seven (7) feet in height and/or within residential districts require a Zoning Permit with the City of Maricopa."[3] The permit verifies the wall's location and exterior design.[3]
Retaining walls over 4 feet need a commercial permit.[3]
Requests go through the city's SmartGov portal.
Flagstaff
Flagstaff exempts fences up to 7 feet from a building permit, but they still need a zoning permit. Retaining walls up to 4 feet, measured from the bottom of the footing, are also exempt from a building permit. They may still need a zoning permit.[4]
Taller walls need a permit.
Applications go through the Flagstaff citizen portal. See our Flagstaff page for other jobs.
Side-by-Side Comparison
| City | Permit trigger | Permit type named | Source |
|---|---|---|---|
| Phoenix | Over 3 ft; over 7 ft needs structural design | Building permit | City page |
| Chandler | Retaining over 4 ft; fence over 7 ft or on a retaining wall | Permit | City page |
| Maricopa | Under 7 ft or in residential districts; retaining over 4 ft | Zoning permit; commercial permit | City page |
| Flagstaff | Fence over 7 ft; retaining over 4 ft; zoning permit may apply | Building and/or zoning permit | City page |
Cities to Check Directly
Check with your city's permit office before you build. Each link goes to the city's own permit information:
- Mesa, Scottsdale, Glendale, Peoria, Goodyear and Queen Creek
- San Tan Valley (Pinal County), Tucson, Yuma, Prescott and Lake Havasu City
- Gilbert, Tempe, Surprise, Avondale and Buckeye: call the city's building department
Reading the Thresholds
Online advice often blurs separate triggers. A height above which a building permit applies is one thing. A zoning permit, which checks location and design, is another. Engineered or structural design is a third.
Phoenix shows how they split: a permit above 3 feet, and structural design above 7 feet.[1] Maricopa shows a zoning permit that applies even to walls under 7 feet.[3]
Ask for the city's rule in writing, and confirm it before you pour a footing.
Retaining Walls Are Treated Differently
A wall that holds back soil is not judged like a freestanding privacy wall. Phoenix exempts retaining walls up to 3 feet unless they carry a surcharge.[1] Chandler and Flagstaff use 4 feet, measured from the bottom of the footing.[2][4] Maricopa sends retaining walls over 4 feet to a commercial permit.[3]
Depth
Retaining wall height before a permit applies
Ground level
- 3 feetPhoenix
- 4 feetChandler
- 4 feetFlagstaff
- 4 feetMaricopa
The stretch from the ground down to the first level is shortened; the distances between levels are to scale.
Finding the Right Authority
The rules above apply inside each city's limits. A parcel outside city limits falls under the county.
Confirm your parcel's jurisdiction with the city or county before you rely on any threshold.
Hiring for the Wall
Ask who handles the permit, plans and inspections, and get it written into the contract.
Before you hire, use our guide to checking a contractor license. If the wall is part of a pool barrier, see our pool barrier data. For other jobs, the permit rules by city page lists more.
Quick answers
Does Phoenix require a permit for a block wall?
Not for fences 3 feet or less. Above that you need a building permit, and fences over 7 feet need structural design.
Does Maricopa require a permit for walls under 7 feet?
Yes. Walls under 7 feet or in residential districts need a zoning permit.
At what height does Chandler require a permit for a retaining wall?
Over 4 feet, measured from the bottom of the footing to the top of the wall.
Sources
- City of Phoenix. "Phoenix: block wall permit." https://www.phoenix.gov/content/dam/phoenix/pddsite/documents/trt/external/dsd_trt_pdf_00181.pdf. Accessed October 22, 2026.
- City of Chandler. "Chandler: block wall permit." https://www.chandleraz.gov/sites/default/files/departments/development-services/City-of-Chandler-Home-Owners-Building-Permit-Manual.pdf. Accessed October 22, 2026.
- City of Maricopa. "Maricopa: block wall permit." https://www.maricopa-az.gov/files/assets/city/v/1/development-services/documents/handouts-guidelines-resources/walls-and-fences-guide.pdf. Accessed October 22, 2026.
- City of Flagstaff. "Flagstaff: block wall permit." https://www.flagstaff.az.gov/DocumentCenter/View/14750/When-is-a-building-permit-needed. Accessed October 22, 2026.