Service Entrance Clearances: The Numbers Inspectors Check First

Inspectors Check Clearances Before They Check Anything Else

On a service upgrade or new service walk, the inspector is usually at the meter and mast before they open a single panel cover. Get the clearance numbers wrong and everything else you did right doesn't matter — you're re-scheduling. Here are the numbers I check myself before I ever call for inspection.

Overhead Service Conductor Clearance: 230.24

This is the one that gets missed most on additions and re-roofs that change grade or roofline. NEC 230.24(B) sets minimum vertical clearances for overhead service conductors above finished grade:

• 10 feet — at the electrical service entrance to buildings, at the lowest point of the drip loop, and above areas accessible only to pedestrians, measured from final grade, sidewalks, or platforms, for 0-150 volts to ground.
• 12 feet — over residential property and driveways, and commercial areas not subject to truck traffic, for 0-300 volts to ground.
• 15 feet — for those same areas at 301-600 volts to ground.
• 18 feet — over public streets, alleys, roads subject to truck traffic, parking areas subject to truck traffic, and other areas traversed by vehicles such as cranes.

The number I see busted most is the 12-foot residential driveway clearance — additions that extend a driveway or a re-grade that raises the ground under an existing drop can put a previously compliant service into violation without anyone touching the mast.

Clearance From Building Openings: 230.9

Service conductors need a minimum of 3 feet of clearance from windows that are designed to open, doors, porches, balconies, ladders, stairs, fire escapes, or similar. That 3-foot clearance doesn't apply to a window above the point of attachment that isn't designed to open, but I always confirm with the inspector on borderline cases — some read "designed to open" strictly, some don't. This is the rule that determines whether the meter and mast can go where the homeowner wants it, so I check it before the customer sets their heart on a location.

Working Space: 110.26

This one applies to the panel itself, not just the service drop. 110.26(A)(1) requires a minimum depth of working space in front of electrical equipment likely to require examination, adjustment, servicing, or maintenance while energized — generally 3 feet for equipment up to 150 volts to ground, more for higher voltage depending on conditions. Width needs to be the width of the equipment or 30 inches, whichever is greater, and headroom (110.26(E)) needs to be 6.5 feet minimum. I've failed my own rough-ins mentally walking a panel location past a water heater or into a stairwell landing before the inspector ever had to say anything — it saves the callback.

Service Disconnect Location: 230.70

The service disconnecting means has to be installed at a readily accessible location, either outside the building or inside nearest the point of conductor entrance — and since the 2020 cycle, 230.85 requires emergency disconnects for one- and two-family dwellings to be located outside, readily accessible, and marked, which has become a bigger deal on service upgrades in jurisdictions that adopted it. Check whether your state amended this requirement before assuming it applies.

Grounding Electrode Conductor Routing: 250.64

Not a spacing clearance in the same sense, but inspectors check it in the same walk — GEC runs need to be protected where exposed to physical damage and can't have unnecessary splices unless irreversible compression connections or exothermic welds are used.

Meter Height

NEC doesn't set meter height directly — that's a utility company standard, not code, and it varies by serving utility. Always pull the utility's service requirements sheet, not just the NEC, before rough-in. I've seen a technically NEC-compliant install still get rejected because it didn't match the utility's meter height spec.

Field Note

Before calling for a service inspection, walk the whole path yourself with a tape measure: drip loop height, distance from the nearest opening window, working space in front of the panel, and headroom. It takes ten minutes and it's the difference between a same-day pass and a two-week reschedule.