Scottsdale Block Wall, Fence, and Retaining Wall Permits: When You Need One

Scottsdale runs three separate height triggers for walls, and one of them has no height at all. A fence needs a permit past 3 feet. A dry-stack or interlocking block wall needs one past 30 inches. A retaining wall needs a permit and a stamped engineer's design at any height, even 18 inches. Everything below those lines stays permit-free but still goes past the city, through a free site plan check that keeps the wall off easements and out of the drainage path.

The three permit triggers

You need a Scottsdale building permit once a wall or fence crosses one of three lines. The city lists the jobs that require a permit:

Constructing any fence taller than 3-feet in height Building dry stack stone or interlocking block walls over 30-inches in height Constructing a retaining wall

So the fence trigger is 3 feet, the dry-stack or interlocking block wall trigger is 30 inches, and a retaining wall needs a permit at any height. The block-wall number sits lower for a reason: units stacked or interlocked without mortar topple more easily than a mortared or engineered wall. Two cases catch people out. Replacing an existing fence counts as new construction under the same rules. Adding height to a fence already over 3 feet needs a permit too.

The walls you can build without a permit

Walls and fences 3 feet and under skip the permit. They do not skip the city. Scottsdale still runs a courtesy site plan check:

In most residential zoning districts, you do not need a permit for walls and fences (including wrought iron fencing), up to 3' in height.

The review is free and quick. It confirms the wall meets your zoning, stays clear of any easement or drainage watercourse, and does not push water onto a neighbor. Your zoning district sets both how tall a wall may be and how close to the property line it may sit, and those setbacks are covered in Scottsdale residential zoning and setbacks. A short decorative wall along a front yard is the classic no-permit case, as long as it clears the site plan check.

Retaining walls and engineering

The retaining wall is the one type with no exemption at any height. It holds back soil, so it carries load and can fail in a way a free-standing garden wall cannot. Scottsdale requires engineered plans for every one of them, stamped by an Arizona-licensed engineer or architect. There is a shortcut on the low end. For a wall 4 feet or less, the city publishes a standard detail, its Minimum Standards for Retaining Walls 4 ft. high or less, and you can build to that instead of paying for a custom design. A retaining wall submittal also needs a full grading and drainage plan showing top-of-wall and finished-grade elevations along the wall.

Scottsdale's fee structure is worth reading before you design. The city bills retaining wall review by the hour plus a charge per linear foot, and it collects the first hour of plan review when you submit. Length drives that fee, not height, so a long low terrace can review more expensively than a shorter, taller wall doing the same job.

A north Scottsdale hillside case

Suppose a homeowner on a sloped north Scottsdale lot wants a 5 foot privacy wall along the back and a low retaining wall to level a side-yard patio. The 5 foot wall clears the 3 foot line, so it takes a permit. The retaining wall takes a permit and an engineer no matter how short it is. At 3 feet it fits the city's standard 4-foot detail, so the engineer builds to that rather than a custom design and the cost stays down. The submittal puts both walls on a grading plan with top-of-wall and finished-grade elevations, shows neither wall sitting on the utility easement, and carries the engineer's stamp on the retaining wall. The privacy wall sits on a footing sized for the soil under it.

Before you set a string line

Measure first, and measure from the low side. A fence at 3 feet or under, or a garden wall at 30 inches or under, stays permit-free and still gets the free courtesy site plan check. An inch over puts you in permit territory. Treat any retaining wall as a permitted, engineered job from day one, and reach for the city's standard 4-foot detail whenever the wall is low enough to qualify. Keep every wall off your easements and out of the drainage path, because that is exactly what the courtesy review looks for. If the wall encloses a pool yard, it gets reviewed with the pool, as covered in the Scottsdale pool and spa barrier permit. Permit and review fees are itemized in the Scottsdale permit and impact fee schedule.

Source

The permit triggers, the 3 foot and 30 inch thresholds, the courtesy site plan check, and the retaining wall engineering and fee rules are published by the City of Scottsdale on its Walls and Fences page and its Permit Services page. The standard retaining wall detail is the city's Minimum Standards for Retaining Walls 4 ft. high or less. Retaining walls are engineered to the building code Scottsdale adopts, tracked in the ICC code adoptions for Arizona.

Height thresholds and the retaining wall fee formula both get revised. Take your wall lengths and elevations to Scottsdale Planning and Development for the live numbers before you order block.