Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Fences over 6 feet, any fence in a front yard, masonry walls over 4 feet, and all pool barriers require a permit from Arnold's Building Department. Most rear-yard wood/vinyl/chain-link fences under 6 feet are exempt.
Arnold enforces a strict 6-foot height cap on residential fences in side and rear yards, with a reduced setback requirement on corner lots that triggers front-yard fence permits even for shorter installations. Unlike many Missouri municipalities, Arnold's zoning code specifically addresses corner-lot sight triangles and requires that any fence visible from the public right-of-way meet a 3-foot maximum height within the sight triangle—a rule that catches many homeowners off guard on corner properties. The city's online permit portal (managed through Arnold City Hall) offers same-day over-the-counter approval for standard rear-yard fences under 6 feet with no masonry component, but masonry fences and pool barriers demand a formal site plan with property lines, footing details, and gate specifications. Arnold sits in FEMA flood zone AE in the bottoms near the Meramec; if your property is in a flood-prone area, the Army Corps may require additional setback certification. The 30-inch frost depth typical of Arnold's loess soils means fence post holes must exceed frost depth to prevent heave; inspectors will verify post depth on masonry installations.
What happens if you skip the permit (and you needed one)
- Stop-work order plus a $250–$500 fine from Arnold Building Department; you'll owe a reinstatement fee ($75–$150) on top of the original permit fee if you want to legalize the fence.
- Fence removal ordered within 30 days if it violates height or setback; removal cost ($2,000–$8,000 for labor and materials) falls entirely on you.
- Title insurance claim denial on sale; title companies in Missouri flag unpermitted fences in TDS (Transfer Disclosure Statement), and buyers' lenders often will not fund until the fence is permitted retroactively or removed.
- HOA fines (if applicable) ranging $50–$200 per month; HOA enforcement is separate from the city, but they can pursue liens if fines go unpaid.
Arnold fence permits — the key details
Arnold's Building Department enforces a two-tier height standard: 6 feet maximum in side and rear yards, and 3 feet maximum within the corner-lot sight triangle (typically a 50-foot radius from the corner intersection). The sight-triangle rule exists under Arnold's local zoning ordinance and is designed to prevent driver-sight obstruction at intersections; many homeowners think the 6-foot rule applies everywhere, then discover mid-construction that their corner lot is subject to the stricter 3-foot cap in the front/side area closest to the street. If your property abuts a corner lot or is itself a corner lot, request a sight-line drawing from the Building Department (usually $25–$50) to confirm exactly where the 3-foot zone begins; this simple step prevents costly teardowns.
Pool barrier fences are always permitted, regardless of height, and must meet International Building Code (IBC) Section 3109 requirements: self-closing and self-latching gates that open away from the pool, vertical bar spacing no greater than 4 inches, and footing depth at least 30 inches below finished grade in Arnold (per soil frost depth). The pool barrier permit application requires a site plan with the pool's location, the fence's location, gate swing, and latch mechanism. Many homeowners assume a 4-foot pool fence is exempt if it's in the rear yard; it is not. Arnold Building inspectors will conduct a footing inspection before any pool barrier is signed off, and they will reject any gate that does not latch automatically or any spacing wider than 4 inches.
Masonry fences (brick, stone, or concrete block) over 4 feet require an engineer's footing detail and a formal permit application regardless of whether they are in a front, side, or rear yard. Arnold's 30-inch frost depth means footing must extend at least 32 inches below the finished grade; inspectors will require a footing inspection before the wall is backfilled. Masonry fence permits typically take 2-3 weeks because the Building Department reviews the engineer's stamp and verifies the footing depth with a site visit. Many DIYers attempt masonry walls without engineering; the city will issue a stop-work order and demand that you hire an engineer ($800–$2,000) to certify retroactively.
Replacement of an existing fence with the same material and height does not require a permit if the fence is in a side or rear yard and is under 6 feet—a key exemption for Arnold homeowners. If you are replacing a 5-foot wood fence with a new 5-foot wood fence in the same location, you do not need to file. However, if you are increasing the height or changing material (e.g., wood to vinyl to a lattice-topped design that pushes it to 7 feet), a permit is required. If the original fence encroaches into a setback or violates the sight-triangle rule, you cannot simply replace it in the same location; you must correct the violation as part of the replacement, which then requires a permit application.
Arnold allows owner-builder pulls for fences on owner-occupied residential property; you do not need a licensed contractor to apply for or construct a fence permit. However, if your property is in a homeowners association (HOA), you must obtain HOA approval BEFORE filing the city permit. Many homeowners apply to the city first and are denied at the last moment because the HOA withheld approval; the Arnold Building Department will not issue a final permit without proof of HOA sign-off if your property is governed by an HOA covenant. Check your deed or contact your HOA before you spend any time on a city application.
Three Arnold fence (wood/vinyl/metal/chain-link) scenarios
Scenario A
5-foot wood privacy fence, rear yard, single-family home in central Arnold (off Jeffco Blvd)
You are replacing an old wood fence with a new 5-foot pressure-treated pine privacy fence in your rear yard. The fence is not masonry, does not serve as a pool barrier, and is not in a front yard or corner-lot sight triangle. Arnold's replacement exemption applies: no permit required. You do not need to contact the Building Department, file any paperwork, or schedule an inspection. You can purchase materials, hire a contractor or DIY, and install the fence immediately. The only contingency: if your property is part of an HOA, check your CC&Rs (Covenants, Conditions & Restrictions) first; some HOAs require written approval for fence work even if the city does not. If no HOA applies, you are clear to proceed. Cost is materials and labor only; no permit fees. Timeline is zero days for permitting.
No permit required (≤6 ft rear-yard replacement) | Pressure-treated posts 4x4, 30 inches into frost | 6-foot material cost $3,500–$6,000 | Labor (if hired) $2,000–$4,000 | Total project $5,500–$10,000 | No permit fees | No inspection required
Scenario B
6-foot vinyl privacy fence wrapping a corner lot at Raintree and Westwood (sight-triangle conflict)
You own a corner lot in Arnold and want to install a 6-foot white vinyl privacy fence along both the front and side of your property to shield your yard from busy street traffic. The Building Department will require a permit because your corner lot is subject to the sight-triangle rule: you can only build 3 feet high within approximately 50 feet of the corner intersection (the exact distance is specified in Arnold's zoning map). You will need to file a site plan showing your property lines, the location of the corner, the sight-triangle boundary, and the proposed fence height in each zone. The application will likely be rejected if you propose 6 feet in the sight triangle; you will have to revise the plan to show either a 3-foot fence in the sight triangle or a stepped design (3 feet near the corner, stepping to 6 feet as you move away). Once the plan is approved, you can proceed to installation. A footing inspection is not required for vinyl (no engineering required), but the inspector will verify height and alignment at final walk-through. Cost includes a $100–$150 permit fee, site plan preparation ($300–$600 if hired), vinyl material ($6,000–$9,000 for 200+ linear feet), and labor ($2,500–$5,000). Timeline is 2-3 weeks for plan review and approval, then 1-2 weeks for construction and final inspection.
Permit required (corner-lot sight triangle) | Site plan with property lines and sight-triangle boundary required | 3-foot fence in sight triangle, 6-foot elsewhere | Vinyl material $6,000–$9,000 | Permit fee $100–$150 | Site plan prep $300–$600 | Total project $8,800–$14,750 | Final inspection only
Scenario C
5-foot brick masonry fence, rear yard, multi-family zoned property near Meramec bottoms
You want to build a 5-foot brick fence along your rear property line to match your house's masonry. Even though the fence is under 6 feet and in a rear yard, it is masonry and therefore requires a permit under Arnold's code (masonry walls over 4 feet require a permit and engineer review). You must hire a structural engineer to prepare a footing detail; the detail must show that the footing extends at least 32 inches below finished grade (Arnold's 30-inch frost depth plus 2-inch margin). The engineer will stamp the detail, and you submit it with your permit application. Arnold's Building Department will review the engineering and schedule a footing inspection before you backfill. The inspector will verify that the footing hole is dug to the correct depth and that the concrete footing is properly placed. If your property is in FEMA flood zone AE (common in the Meramec bottoms), the inspector may also ask for a survey showing the footing is above the flood elevation; this requires additional certification ($200–$400). Brick masonry fences typically take 3-4 weeks for plan review plus 2 weeks for footing inspection, then another 2-3 weeks for the mason to build. Total cost includes engineering ($1,200–$2,000), permit fee ($150–$200), materials ($5,000–$8,000), masonry labor ($3,000–$6,000), and potential flood-zone survey ($200–$400). Total project $9,550–$16,600.
Permit required (masonry >4 ft) | Structural engineer footing detail required ($1,200–$2,000) | Footing depth 32 inches minimum (frost depth 30 in. + margin) | FEMA flood-zone survey may be required ($200–$400) | Brick material $5,000–$8,000 | Masonry labor $3,000–$6,000 | Permit fee $150–$200 | Footing inspection required | Total project $9,550–$16,600 | Timeline 7-9 weeks
Every project is different.
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City of Arnold Building Department
Contact city hall, Arnold, MO
Phone: Search 'Arnold MO building permit phone' to confirm
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Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current fence (wood/vinyl/metal/chain-link) permit requirements with the City of Arnold Building Department before starting your project.
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