While the ideal situation is to have a standard building code across the whole of the country, that's never going to happen somewhere as large and diverse as the US. But it means you have to be careful you know the regulations you're working under for every project you undertake.
Developing Multiple Codes
For most of the 20th Century, building regulations were based on model codes developed by three organizations -- Building Official Code Administrators (BOCA) on the East Coast and Midwest, Southern Building Code Congress International (SBCCI) for the Southeast and the International Conference of Building Officials (ICBO) on the West Coast across to the Midwest. By the early 1990s, attempts were made to create a single set of national codes, culminating in the formation of the International Code Council (ICC) in 1994. That led to the publication of the International Building Codes (IBC) in 1997, developed from the three previous codes.
Although the National Fire Protection Association (NFPA) initially joined ICC to develop the International Fire Code, disputes arose and the NFPA discontinued participation. Instead, it joined with other organizations to create an alternative set of codes, the Comprehensive Consensus Codes (C3).
The outcome of this is some states have based their building codes on the IBC while others have adopted C3. Furthermore, individual states and counties have adapted the model codes to meet their individual needs, so there's a real variety across the country.
Code Update and Enforcement
Every state and county or municipal government may have developed its own codes that it will enforce at the appropriate level. There may be various codes to cover specific projects, such as general building codes for commercial or residential, energy conservation, fire prevention, mechanical and electrical.
The ICC codes are typically updated and reissued every three years. Although the state and county codes are usually updated in line with changes, this happens afterwards and the period of delay may vary. Consequently, the model versions used are not the same.
The enforcement of the codes is the responsibility of government officials. However, while codes set minimum standards, they often don't impose limits on materials and methods, so you may use alternatives if you can prove they're of equal or better quality.
Plan and Prepare
Before you start any project, since most are different in some way or in other jurisdictions, you need to check and confirm the actual code you're working under and how it will affect you. To do this:
- contact the most local government body -- either your local building inspection department, office of planning and zoning or department of permits -- to identify the codes that affect your project
- determine any local changes or modifications
- ascertain if your project, due to particular features, is also subject to state or federal requirements
- access state or county government pages to see code, license and permit details.