Guide 04 · 5 min read
Do You Need a Permit for a Retaining Wall in Scottsdale?
A retaining wall in Scottsdale needs a permit, engineered plans and a review before anyone digs.
Rules
Do you need a permit for a retaining wall in Scottsdale?
Yes, every retaining wall needs engineered plans submitted to and approved by the city, with no height exception in the rule (City of Scottsdale, walls and fences (opens in a new tab)). That includes the 18 inch wall holding up a planting terrace. The plan set has to come from an engineer and show the footing, the drainage and the soil assumptions behind the design. A block wall built without that approval is unpermitted work, and it can become a problem at resale when a buyer's inspector asks for the permit. The cost of doing it in order is a drawing and a review. The cost of skipping it can be removal, or a sealed engineering assessment followed by review, a permit and an inspection, on a wall that was built to nobody's design.
Rules
What counts as a retaining wall, and what height needs a permit?
A retaining wall holds soil back and creates a grade change. A garden wall or a seat wall sits on top of the ground and holds nothing but itself, so it follows the fence and wall rules rather than the retaining wall rules. A fence or wall over 3 feet needs a permit, and a dry stack wall over 30 inches needs one too. A wall up to 3 feet still needs courtesy site plan approval, which is a zoning and stormwater check rather than a full permit (walls and fences (opens in a new tab)). Site walls at the property line are limited to 6 feet in a required side or rear yard (single family site plan requirements (opens in a new tab)).
Rules
What does the engineering review look at?
The city's retaining wall policy sets the assumptions the engineer designs to. Footings have to bear a minimum of 18 inches below undisturbed soil or engineer certified fill (City of Scottsdale, retaining wall policy (opens in a new tab)). The policy lists default soil values for the review unless a soil report for the site is submitted, and the city highly recommends a geotechnical investigation for foundation design. The set also has to show positive drainage at the wall, and calculations are required where a surcharge is present, such as a driveway or roadway beside the wall. Revisions can come from a wall drawn for its height but not for the driveway, the pool or the slope above it.
Hardscape
How far does the wall have to sit from the property line?
At least 3 feet from the property line, or 1 foot for each foot of total depth and height, measured from the bottom of the footing to the top of the wall (single family site plan requirements (opens in a new tab)). A wall that measures 6 feet from the bottom of the footing to the top sits at least 6 feet off the line. Measure from the property line rather than the fence, because the two are not always in the same place on an older lot. A site wall on the property line follows a separate height limit in a required side or rear yard. On a small lot, the setback decides whether the wall is buildable at all.
Rules
What changes on ESL or NAOS land?
On land inside the Environmentally Sensitive Lands overlay, part of the site is mapped as Natural Area Open Space, and inside that area no grading, filling, clearing or excavation is permitted, and structures including walls may not be built (City of Scottsdale, NAOS guide (opens in a new tab)). A retaining wall is a structure, so a wall that crosses NAOS is out, and a wall that edges it has to be drawn to show the limit. The easement stays with the property after a sale, and the city's guide says a portion can be released only if an equal amount of natural desert is dedicated as replacement. The overlay is mapped by parcel, so the answer is specific to your lot. Before design, pull that map and have the NAOS line surveyed. A wall designed to the wrong line is a redesign, not a revision.
Ground
How does the wall handle drainage and washes?
Water is a common point of failure. A wall has to pass the water that collects behind it, through weep points and drained backfill, and the grade above has to be shaped so water arrives at those points instead of saturating the soil. Washes complicate it. The city prefers to keep washes in their natural state in the northern part of Scottsdale, and an obstruction in a wash can send stormwater outside its natural path, causing erosion and flooding (City of Scottsdale, wash ownership and maintenance (opens in a new tab)). A wall placed in or across a wash is that obstruction. The city says to trim trees and large shrubs so limbs are 3 feet above the bottom of the wash, and to inspect washes at least annually and after any storm that produces flow. Near a wash, the drainage plan and the setback are the 2 drawings to get right.
How it works
What order should the work happen in?
Survey first, and a soils report where the site calls for one: the city highly recommends a geotechnical investigation for foundation design and requires a soil report for compressible or expansive soil, and the wall cannot be placed without the property line and the NAOS limit. Then drawings, submittal, review, permit, excavation. Review time varies with the city's workload; a set that comes back for corrections adds a cycle. Anything found in excavation that the report did not predict, such as rock or a buried utility, can send the drawing back for a revision.
4 questions
Questions people ask
Still have a question? Call (747) 243-2089 and describe the yard.
Can I build a retaining wall myself?
The permit and the engineered plans are required whoever builds it. Whether you can act as your own owner builder is a question for the permit counter, and the answer depends on the property and the scope. The review is the same either way. Ask before you buy material.
Does a wall under 3 feet need a permit?
A wall up to 3 feet goes through courtesy site plan approval, a zoning and stormwater check rather than a full permit. A retaining wall at that height still needs a permit and engineered plans under the city's walls and fences rules. Ask the counter which path your wall takes before the design is finished.
How long does the review take?
Review time varies with the city's workload and how complete the set is. The part you control is the package: soils report, footing detail, drainage, and a survey showing the property line and any NAOS limit. A set missing one of those can come back for corrections, which adds a review cycle.
What happens if a wall is built without a permit?
It is unpermitted work, and that can surface at resale, at a refinance or when a neighbor complains. The city's fix is a sealed assessment from an engineer or architect, followed by review, a permit and an inspection, and the wall stays in violation until those steps are done. That path can cost more than the review that was skipped.
