Building Codes
The International Building Code (IBC) is a Model Building Code published by the International Code Council and is revised every 3 years. Local authorities incorporate a version of the IBC into official city, county or state building codes. For example, at the time of this writing, Illinois is using the Illinois Building Code 2021, based on IBC 2021. If your site is in Illinois, you’d build to IBC 2021 unless the county or city has a superseding code such as Chicago, using the Chicago Building Code 2019, based on IBC 2018.
Call your local building official to see which version of the IBC they require for your site location. You can look online, but the required IBC version is often not listed and you may have to talk to someone to find out which one will be current at the time of installation. There are 3rd party websites that list building codes but they are not guaranteed to have the correct information.
Frost depth requirements are also needed from the local building official to determine the minimum post footing depth to prevent frost heaving.
Building codes typically don’t directly dictate anything about fence design beyond at what height a permit is required and the design of post footings, but ask if there are any local requirements just to be sure.
The version of the IBC that needs to be used is important as it dictates which Reference Standards that are required to be used which are updated every 3 to 6 years.
- ASCE 7 for wind and ice forces
- AISC 360 for schedule 40, 80 & 120 pipes, and square tubes with 1/8” or greater wall thicknesses
- AISI S100 for sheet metal tubes and channels
- ADM for aluminum posts
- NDS for wooden posts