The scope of the International Building Code® (IBC®) includes all buildings except detached one- and two-family dwellings and townhouses up to three stories.

The 2018 IBC contains many important changes such as:

Accessory storage spaces of any size are now permitted to be classified as part of the occupancy to which they are accessory.
New code sections have been introduced addressing medical gas systems and higher education laboratories.
Use of fire walls to create separate buildings is now limited to only the determination of permissible types of construction based on allowable building area and height.
Where an elevator hoistway door opens into a fire-resistance-rated corridor, the opening must be protected in a manner to address smoke intrusion into the hoistway.
The occupant load factor for business uses has been revised to one occupant per 150 square feet.
Live loads on decks and balconies increase the deck live load to one and one-half times the live load of the area served.
The minimum lateral load that fire walls are required to resist is five pounds per square foot.
Wind speed maps updated, including maps for the state of Hawaii. Terminology describing wind speeds has changed again with ultimate design wind speeds now called basic design wind speeds.
Site soil coefficients now correspond to the newest generation of ground motion attenuation equations (seismic values).
Five-foot tall wood trusses requiring permanent bracing must have a periodic special inspection to verify that the required bracing has been installed.
New alternative fastener schedule for construction of mechanically laminated decking is added giving equivalent power-driven fasteners for the 20-penny nail.
Solid sawn lumber header and girder spans for the exterior bearing walls reduce span lengths to allow #2 Southern Pine design values.