Electrician Questions — technical NEC analysis for electricians, apprentices, and inspectors.
The question: I got a notice that overhead service conductors are too low in a resident’s backyard. I always thought the minimum was 10 feet. The utility wants 12 feet over grass with no driveway. I’ve never had to go that high. Who is right?
Short Answer
For a residential backyard (not merely a pedestrian sidewalk), NEC 225.18(B) requires 12 feet — not 10 feet. The 10-foot clearance in 225.18(A) applies to finished grade, sidewalks, and pedestrian-only areas — not the general lawn area of a residential lot. The power company is aligned with NEC for residential property. Utilities may also impose NESC clearances that meet or exceed NEC.
NEC 225.18 — Full Clearance Table
| Section | Area below conductors | Minimum height |
|---|---|---|
| 225.18(A) | Finished grade, sidewalks, pedestrian-accessible areas only | 10 ft (3.0 m) |
| 225.18(B) | Other areas of residential property and driveways | 12 ft (3.7 m) |
| 225.18(C) | Public streets, roads, parking areas subject to truck traffic | 18 ft (5.5 m) |
Side-View Diagram — Backyard vs Sidewalk
SIDE ELEVATION
Service conductors ═══════════════════
│
12 ft (225.18(B)) │ ← Residential backyard (grass)
─────────────────────┼────────────── grade
│
10 ft (225.18(A)) │ ← Public sidewalk only (pedestrian)
─────────────────────┼────────────── sidewalk
Why Electricians Remember “10 Feet”
The 10-foot rule is real — but it is narrowly scoped to pedestrian paths. Backyard lawn on a single-family lot is “other areas of residential property” under 225.18(B). No driveway is required to trigger 12 feet; the driveway language is in addition to the rest of the residential lot.
Bar Chart — Clearance by Area Type
Sidewalk / pedestrian
Residential yard
Streets / truck areas
NEC vs Utility (NESC) — Who Governs?
| Authority | Document | Typical role |
|---|---|---|
| AHJ / electrical inspector | NEC 225.18 | Service / premises wiring clearance at point of attachment |
| Utility company | NESC (IEEE C2) | Utility-owned conductors — may require equal or greater clearance |
Field Fix Options
- Raise point of attachment / mast to achieve 12 ft at lowest point over grade.
- Relocate service route to avoid low sag over usable yard area.
- Coordinate with utility for re-sag, pole adjustment, or service relocation.
- Document measurements from finished grade to conductor lowest point at maximum sag (temperature-adjusted if utility specifies).
Bottom Line
A grass backyard on residential property is 12 feet minimum under NEC 225.18(B). The 10-foot rule does not apply to that area. The utility notice is consistent with NEC — your prior 10-foot assumption likely came from mixing pedestrian-area and residential-property sections.
References: NEC 225.18, 230.54 (service conductor attachment). Utility requirements may also reference NESC Rule 232. Verify with serving utility and AHJ.