The panel fits the wall. Does the wall pass? On a service upgrade or a rough-in, the space around the panel fails inspection more often than the wiring inside it. NEC 110.26 governs that space, and it is dimensional — the inspector shows up with a tape measure, not an opinion. Here is what has to be clear, and the things that get red-tagged.

The working space: three dimensions

NEC 110.26(A) sets a required working space in front of equipment likely to be serviced while energized — which is exactly what a panelboard is. It has three measurements, and all three have to be satisfied at once.

Depth — 3 feet in front. A residential 120/240 V service is 120 V to ground, which puts you in the "0 to 150 volts" row of Table 110.26(A)(1). That row is 3 ft for all three conditions — so for a house panel the answer is simply 36 inches of clear depth in front of the panel, measured from the face of the deadfront out into the room. (The "conditions" that increase the depth only kick in above 150 V to ground — commercial/industrial gear, not a dwelling.)

Width — 30 inches. NEC 110.26(A)(2): at least 30 in wide, or the width of the panel if it is wider than 30 in, and the deadfront or door has to be able to swing a full 90°. The 30 in does not have to be centered on the panel, but it does have to be a clear 30.

Headroom — 6 ft 6 in. NEC 110.26(A)(3): the working space has to be at least 6 ft 6 in high (or the height of the equipment, if that is taller).

Miss any one of the three and the space fails, even if the other two are generous. The most common failure is depth: a panel in a narrow utility closet with the water heater or furnace eating into that 36 inches.

Where a panel is not allowed to go

This is about location and access, not load. The breakers have to be readily accessible — reachable without moving obstacles, standing on a chair, or using a ladder — and NEC 240.24(A) caps the height: the center of the grip of the highest breaker's operating handle can't sit more than 6 ft 7 in above the floor or working platform. Panels set too high for a finished-basement ceiling are a routine correction.

They also can't go in the wrong room. In a dwelling, the panel can't be in a bathroom (NEC 240.24(E)), and it can't be in the vicinity of easily ignitible material such as a clothes closet (NEC 240.24(D)). Both are common finds on older-home remodels where the panel was "always there."

Dedicated equipment space — the volume above the panel

This is the rule people confuse with working space, and it is different. NEC 110.26(E) reserves the space above the panel — a footprint equal to the width and depth of the equipment, running from the floor up to 6 ft above the panel, or to the structural ceiling if that is lower. Nothing foreign is allowed in that zone:

  • No plumbing, drains, or gas piping
  • No HVAC ducts
  • No leak-protection systems or other equipment unrelated to the electrical installation

Working space (in front) is about a person being able to stand and work. Dedicated space (above) is about keeping a leaking pipe or a duct off the top of the panel. Inspectors check both, and a condensate line or sprinkler pipe run across the top of a panel is an easy catch.

The circuit directory

NEC 408.4(A) requires every circuit to be legibly identified as to its clear, evident, and specific purpose, on a directory located on the face or inside of the panel door — and spare positions with unused breakers have to be labeled as spares, too. "Lights," "plugs," and blanks don't pass. It is the cheapest thing on this list to fix and the easiest to forget, and it will hold your final.

What the inspector actually checks

At rough-in and again at final, this is the walk:

  • Tape the depth — a clear 36 in in front, with the door open and whatever ends up opposite the panel accounted for.
  • Swing the door (and any adjacent door) a full 90° — does it hit the water heater, a shelf, the opposite wall?
  • Look up — anything crossing the 6 ft dedicated space above.
  • Is the space being used for storage? A panel behind stacked boxes isn't "readily accessible."
  • Directory filled in and legible; breakers match the legend.
  • Highest handle within 6 ft 7 in of the floor.

Common red-tag reasons

A door that can't open 90°. A panel tucked behind a swinging door or into a corner where the deadfront can't fully open fails the width rule.

Panel in a clothes closet or bathroom. Still one of the most common corrections on older-home remodels.

The water heater or furnace in the working space. Utility closets get tight; the appliance intruding on the 36 in is a depth failure even if the panel itself is fine.

Storage or finish built over the panel. A soffit, cabinet, or shelf intruding on the dedicated space above.

Blank or vague directory. Cheap to fix, easy to forget, and it will hold your final.

Verify your edition. These figures are the residential (0–150 V to ground) case and are unchanged across the 2017, 2020, and 2023 NEC — but the exact edition your jurisdiction has adopted, plus any local amendments, always governs. Confirm both before you frame the wall. Clearance is separate from capacity: size the service itself with the panel load calculator (NEC 220), then make sure the box has room to live where you put it.