Most Common Construction Code Violations: A Frequency Report
Helonic has analyzed more than 100,000 pages of construction drawings across 1,000+ project reviews, surfacing over 150,000 issues. This report ranks the code sections that get flagged most often at the drawing stage — before a permit set is submitted or a drawing set is issued for construction — so teams know where to look first.
The most-flagged code sections, ranked
The table below ranks the code categories Helonic flags most often by relative frequency within all code-related findings. We report the ranking and rough tiers rather than precise percentages — exact shares move with project type and code edition — but the ordering is stable across our corpus.
| Rank | Code section / category | Relative frequency |
|---|---|---|
| 1 | NEC 110.26 — electrical working space & clearances | Most flagged (~1 in 5) |
| 2 | IBC Ch. 10 — egress width, door swing, travel distance | Very high |
| 3 | ADA / ICC A117.1 §703 — signage & 305 clear floor space | Very high |
| 4 | NFPA 13 — sprinkler obstruction & clearance to deflector | High |
| 5 | IBC Ch. 7 / 707–708 — fire-rated assembly continuity | High |
| 6 | IBC Ch. 11 / A117.1 §404 — accessible doors & maneuvering | Moderate |
| 7 | IMC / IBC — ventilation & equipment access clearances | Moderate |
| 8 | IPC — fixture count & accessible fixture clearances | Moderate |
The pattern that holds across the list: the violations that recur most are the geometric and cross-sheet ones — a clearance, a width, or a count that is correct on one sheet and wrong on another. These are exactly the findings that pair with the broader categories in our most common drawing errors report.
Why NEC 110.26 tops the list
Electrical working-space clearance is the most-flagged single code section because it sits at the intersection of two disciplines that rarely draw the same room at the same scale. The electrical engineer places a panel on the power plan; the architect lays out the room on the floor plan; neither sheet shows the 36-inch depth, 30-inch width, and 6.5-foot headroom that NEC 110.26 requires in front of the equipment. The violation is invisible on either sheet alone and only appears when the two are reconciled.
Our deep dive on NEC panel clearance requirements walks through the working-space, dedicated-equipment-space, and illumination rules in detail, and NEC electrical code checking shows how Helonic flags them automatically.
Egress and accessibility: the two categories on every project
Egress and accessibility rank second and third because they appear on every occupied building regardless of type, and because both require counting and measuring against an occupant load that is itself derived elsewhere in the set. The most common egress findings are doors that swing into required width, corridor widths that don’t satisfy the calculated occupant load, and travel distances that exceed the limit for the occupancy and sprinkler condition. See our reference on IBC egress width requirements for the underlying calculation.
Accessibility findings under ADA and ICC A117.1 cluster around clear floor space at fixtures and doors (Sections 305 and 404), maneuvering clearances, and signage mounting under Section 703. These are catchable on the drawings, which is why accessibility checking and egress compliance are among the most-used checks in the platform.
The wrong-edition trap
A frequency ranking only matters if the review runs against the code edition the authority having jurisdiction actually enforces. Jurisdictions adopt the IBC and NEC/NFPA on their own schedules, often with state amendments, so a set checked against the 2026 NEC can still fail a jurisdiction enforcing an earlier adopted edition. Confirming the adopted edition and local amendments before review is the highest-leverage step in code checking — the same point we make in is AI plan review reliable enough to catch code violations.
How Helonic helps
Helonic reads every sheet of a 2D PDF set and cross-checks the measurable code categories — working-space clearances, egress widths, accessible clearances, fixture counts, and rated-assembly continuity — against the conditions shown on adjacent disciplines. Each finding includes the exact page location and the governing code reference, and can be turned into a draft RFI or plan-review comment. Confirm the adopted edition first, run the set, and let the platform handle consistent first-pass coverage of the categories that recur most.
Practitioner insight
“The clearance violations are never on the electrical sheet or the architectural sheet — they're in the gap between them. Once we started reviewing the panel against the room instead of reviewing each sheet on its own, NEC 110.26 went from our most common field surprise to something we caught in precon.”
— Source: Conversations with electrical engineers and MEP coordination leads at design firms and design-build contractors, synthesized from Helonic's discipline-side interviews, Q1–Q2 2026.
Construction Code Violation FAQ
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Manas Gandhi
Co-founder & CTO, HelonicManas is the co-founder and CTO of Helonic, where he leads engineering and AI research for construction drawing analysis. He works directly with structural, MEP, civil, and fire protection engineers to translate the way they review drawings into AI systems that flag the issues that actually matter in the field. Before Helonic, he built machine learning pipelines for technical document understanding and has spent the last several years interviewing licensed design engineers and discipline leads to ground product decisions in real practice rather than industry assumptions.
- AI for technical document understanding
- Cross-discipline coordination workflows
- Code compliance automation (IBC, NEC, NFPA, IPC, IMC, ASCE)
- Structural and MEP drawing review systems
How this page was researched: Code-violation frequency rankings derived from Helonic's internal review corpus (1,000+ project reviews, 100,000+ pages analyzed, 150,000+ issues identified) through Q2 2026. Results are reported as a relative ranking with rough frequency tiers within the code-and-accessibility category rather than precise shares, cross-referenced with the published structure of the IBC, NEC, NFPA 13/101, and ADA Standards / ICC A117.1. Editions enforced vary by jurisdiction; confirm the adopted edition before relying on any specific finding.
Last reviewed by Manas Gandhi · June 2026