Codes & Permits

Building Code

The set of regulations governing construction quality, safety, and accessibility, adopted at the state and local level.

A building code is the body of law governing how buildings are designed and constructed. In the United States, codes are written as model codes by the International Code Council (IBC for commercial, IRC for residential, IECC for energy) and adopted, sometimes with local amendments, by states and municipalities. The local AHJ enforces the code through plan review, permit issuance, inspections, and certificate of occupancy.

Code compliance is not optional. Work that fails to meet code can be red-tagged, ordered torn out, or denied a certificate of occupancy. The version of the code in effect on the date of permit application typically governs (older versions stay in effect on existing buildings until renovated). Contractors must verify which code edition the AHJ has adopted before bidding, since older or amended editions can change requirements significantly.

Frequently asked questions

What building code applies to my project?+

The version adopted by the AHJ where the project is built. Confirm with the building department before bidding. Many AHJs are 1 to 3 cycles behind the latest IBC, and local amendments are common.

What is the difference between IBC and IRC?+

IBC (International Building Code) governs commercial and multi-family residential. IRC (International Residential Code) governs detached single-family and duplex dwellings up to three stories. Many of the same concepts apply, but the requirements and references differ.

Who enforces building codes?+

The local AHJ (typically the city or county building department, plus separate fire marshal and health department on commercial work). State agencies may enforce specific codes (electrical, plumbing) on top of building department enforcement.

Related terms

IBC

The model building code for commercial and high-rise residential construction in the United States, adopted in some form by all 50 states.

AHJ

The local agency or official with the legal authority to interpret and enforce building, fire, and life-safety codes.

Permit

AHJ-issued authorization to perform specific work on a building. Required before construction begins.

Plan Review

The AHJ's examination of construction drawings for code compliance before issuing a permit.