Building Codes By State: Which US States adopt State Vs Local

In the past few years, both the construction and insurance industries have seen increased scrutiny around code adoption practices. Understanding both the latest local and state codes is critical for accurate roof insurance claims and indemnity payouts. At OneClick Code, we understand that code requirements set at the state level, amended locally, or adopted entirely by city jurisdictions can dramatically affect roofing estimates, permit fees, and project timelines. In this article, we cover how adoption mechanics differ from state to state, and what that means for contractors and adjusters reviewing claims every day.

Whether you're working in a state that strictly enforces statewide codes or one where every municipality writes its own, you’ll quickly understand that a postal address alone is not enough to be compliant. With OneClick Code’s proprietary code database, you’ll be equipped to identify the correct roofing code requirements for any address and avoid expensive mistakes on roof estimates.

Are Building Codes State or Local?

Many roofing professionals assume building codes are standardized within a state. In reality, code enforcement and adoption vary widely — sometimes from one street to the next.

State-Adopted Building Codes:

• Codes are adopted and enforced at the state level
  
• All municipalities follow the same codebook
  
• Minimal or no local amendments are allowed

Local Building Codes:

• Municipalities or counties independently adopt and amend codes
• Even neighboring cities may have different roofing requirements
• Requires more jurisdiction-specific documentation

Why It Matters:
Both state and local codes shape how roofing estimates are written and how claims are settled. Assuming code uniformity without verification can lead to costly errors.

How Building Codes Are Adopted and Updated

Most building codes originate from model codes published by national organizations.

How Model Codes Are Created:

• Organizations like the International Code Council (ICC) publish model codes every 3 years
• Other bodies, such as ASHRAE, NFPA, and ANSI, influence standards for energy, fire, and safety

State vs. Local Adoption:

• Some states adopt model codes statewide, either in full or with amendments
• Local jurisdictions may adopt model codes independently or further amend state-level adoptions

What Triggers Updates:

• Periodic reviews (often every 3–6 years)
• Climate events, insurance pressures, or regional hazard data
• Mandates tied to energy efficiency or federal resilience standards

Building Code Models and Standards

Here are the most widely adopted model codes referenced in U.S. building regulations:

• IBC – International Building Code (commercial)
• IRC – International Residential Code (1–2 family dwellings)
• IECC – International Energy Conservation Code
• IFC – International Fire Code
• IMC / IPC / NEC – International Mechanical Code, Plumbing Code, and National Electrical Code
  • International Plumbing Code (IPC)
  • International Mechanical Code (IMC)
  • National Electrical Code

Each governs a different aspect of construction — and roofing code references often pull from multiple models.

State Code States

In states where building codes are adopted at a state level, there are no cities and counties that have differing codes. No matter if the project is in the hills or in the plains, if a project is in a State Code State the project will have the same building code requirements as the next house. There is not much room for argument between contractors and adjusters in these states over the topic of building codes.

There are 12 states that follow the adoption of building codes at a state level with state amendments, meaning that the state decides on the codebook to adopt and does not allow for the individual cities or counties to make amendments to that code. What the state says, goes. 

States Include: Connecticut, Florida, Indiana, Kentucky, Massachusetts, Michigan, Minnesota, Montana, New Jersey, Ohio, Rhode Island, and Wisconsin.

Please note that Indiana is unique in that part of the State is considered "state-state" and the other part is considered "state-local".

Most U.S. states have municipalities that have differing building codes or amendments.

U.S. Postal Addresses are not an indicator of which municipality has jurisdiction over a property.

Gathering building code information has historically been a manual process, but now OneClick Code can automate building codes for you. 

For the first time ever, identifying the correct jurisdiction and which building codes are adopted at a local level is a reality with the right tools.

How to Find Current Local Building Codes by State?

Steps to Verify the Right Code for a Roofing Project:

1. Don’t assume based on ZIP code or city name
   
2. Identify the true permitting jurisdiction (AHJ)
   
3. Check state-level adoptions and possible local amendments
   
4. Use a verified tool like OneClick Code to pull the full building code profile for any address

OneClick Code eliminates hours of phone calls and PDF hunting — and gives you jurisdiction-backed data in seconds.

About OneClick Data Inc.

OneClick Data Inc. is a trusted data partner dedicated to streamlining the code-sourcing process for all parties in the roofing industry while increasing efficiency and transparency for all stakeholders in construction and restoration. They have the only platform, OneClick Code, to have blazed the trail for data automation of jurisdictional authority for building codes, permit fees, taxes, and manufacturer specifications required for any address nationwide. OneClick Code has been serving customers in the contracting, insurance, and claim adjusting fields by providing instant access to trusted roofing codes with the click of a button. Offering unique reports that can be easily shared between all stakeholders in the roofing claims industry, OneClick Code adds value to all parties and empowers customers to save time and money on every claim. Welcome to restoration intelligence, automated. To learn more, visit www.oneclickcode.com. 

FAQs - Frequently Asked Questions

Q: What does it mean for a state to adopt building codes at the state level?

A: It means the state selects a model code (e.g., the International Building Code) and applies it uniformly across all municipalities without allowing local governments to adopt different codes or make significant amendments.

Q: What is a “State Code with Local Amendments” model?

A: In this approach, the state adopts a base code, but local municipalities are permitted (or required) to pass local amendments to reflect geographic, climatic, or other regional conditions.

Q: Why does understanding the jurisdiction matter for roofing estimates or claims?

A: Because the authority having jurisdiction drives the required building codes. 45% of the time, the jurisdiction does not match the postal address.  If you look up required codes based on postal address and zip code, you are going to be inaccurate a lot of the time.

Q: How can OneClick Code help you navigate complex code changes and requirements?

A: OneClick Code automates the identification of the correct jurisdiction, the code version adopted, and any local amendments for a given address—eliminating the ambiguity and research burden that often causes inaccurate claims and supplements.