Field Note 03 | Shipping Container Permitting Terminology: A Plain-Language Glossary

Quick Summary

Permitting a shipping container building can feel overwhelming because agencies use a variety of acronyms.

This Field Note defines the core vocabulary: AC462, ESR, AHJ, state modular program, TPIA, ComCheck, couponing, red tag, and more … so you can navigate reviews and approvals with clarity and control.

Why Modular Container Permitting Has Its Own Language

If you’ve ever listened to an architect, engineer, or code official discuss a modular project, you may have felt like they were speaking another language.
Code professionals speak a precise dialect designed to prevent misinterpretation. For project owners, that precision can sound like alphabet soup. Code language is filled with acronyms, shorthand, and jargon — and each term carries its own precise meaning.

At Falcon, we like to remind customers that permitting isn’t difficult because people are uncooperative. It’s difficult because the language isn’t familiar and shared (yet).

This Field Note translates that language. Whether you’re new to modular construction or coordinating your first state-level review, understanding these terms will save you time, clarify expectations, and reduce risk.

Core Players in Container Building Codes

How They Work Together

The ICC develops and publishes the IBC and other model codes. AHJs then adopt and enforce the version they’ve chosen.

Since adoption and amendments vary by jurisdiction, the same project might face slightly different requirements across states, counties, or municipalities. That’s why Falcon begins every project by identifying who your AHJ is before any design work starts.

See Field Note 01: Key Permitting Steps for Shipping Container Buildings

How New Building Methods Get Approved

Not every innovation is written into the code the day it’s invented.

That’s where Alternative Means and Methods and evaluation standards come in.

AC462 in Context

AC462 defines how shipping containers are inspected, modified, and documented for structural integrity. It’s what transformed containers from “alternative materials” into code-recognized building modules.

For engineers and inspectors, that single number — AC462 — signals trust, traceability, and compliance.

State Modular Programs: The Other Side of Approval

Why It Matters

AC462 validates the container as a structural building block. State modular approval applies to the finished module, including all factory-installed systems and modifications.

With the structure approved at the factory and the site handled locally, work can happen in parallel — often saving weeks or months compared to traditional construction.

See Field Note 04: State vs. Local—Who Really Has Jurisdiction Over Your Container Project?

Energy and Engineering Terms You’ll Encounter

Words for When Things Go Wrong

Even the best-prepared projects can hit permitting snags. These are the terms you may expect to hear if an issue arises:

Human Translation: What These Terms Mean for You

All this terminology ultimately serves one goal: safety and predictability.

Falcon’s role is to be your guide through the journey and interpreter of the language — to translate between the technical, the regulatory, and the practical, and get your project permitted and occupied to support safe, compliant operations.

Quick Reference Table

Summary: Why Words Matter

Permitting isn’t merely a technical exercise. You might think of it as a conversation between professionals who speak slightly different dialects of the same language. By understanding permitting terminology, you can:

• Anticipate reviewer questions
• Communicate clearly with engineers and AHJs
• Avoid missteps that delay approvals
• Demonstrate credibility with regulators

The right words turn confusion into progress … and progress into approved, occupied buildings.

FAQ: Common Terminology Questions

What does “state modular approval” mean?

State modular approval is the process that allows a certified manufacturer to have a building reviewed, inspected, and approved at the factory under the state’s modular construction program. Once approved, the state issues an insignia label confirming code compliance. Local officials then only review site-specific work like foundations and utilities.

What is AC462 in shipping container construction?

AC462 is the Acceptance Criteria for Structural Building Modules Using Shipping Containers>, published by the International Code Council Evaluation Service (ICC-ES). It defines how modified ISO containers must be engineered, tested, and quality-controlled to be recognized as safe structural building modules under the building code.

What is an ESR number, and why does it matter?

An Evaluation Service Report (ESR) is a third-party verification issued by ICC-ES confirming that a manufacturer meets a specific acceptance criterion like AC462. Falcon Structures’ ESR-4163 proves our containers comply with AC462, giving code officials and engineers documented assurance of safety and quality.

What does “AHJ” stand for in building codes?

AHJ stands for Authority Having Jurisdiction — the agency or official responsible for enforcing building and safety codes. Depending on the project, the AHJ could be a state modular program, a city building department>, or both.

What is the difference between ICC and IBC?

The International Code Council (ICC) creates the rules; the International Building Code (IBC) is the document that compiles them. Most U.S. jurisdictions adopt some version of the IBC and enforce it through their AHJ.

What does “red tag” mean in construction?

A red tag is an official notice from an inspector that halts construction or occupancy because a building doesn’t meet code requirements or lacks permits. Once the issue is corrected and reinspected, the red tag can be lifted.

What is ComCheck, and when is it used?

ComCheck is a U.S. Department of Energy software tool used to verify that a building meets energy-efficiency requirements for insulation, lighting, and HVAC systems, dependent on the building’s final location. Engineers use ComCheck reports as part of state modular plan submittals.

What is “couponing” in container construction?

Couponing means cutting small steel samples>—called coupons—from a shipping container wall or structural element to test its composition, thickness, and strength. Do all states recognize AC462 and ICC ESRs?

Do all states recognize AC462 and ICC ESRs?

Most states with modular programs recognize AC462 and ICC-ESR reports as evidence of compliance, though adoption varies by jurisdiction.

How does Falcon help customers with permitting terminology?

Falcon’s permitting team acts as a translator between codes and construction, preparing compliant documentation and coordinating directly with reviewers and AHJs, so customers can focus on project outcomes instead of decoding regulations.