Construction Type Classification Codes
Construction Type Listed on Permit
A or B | A or B | A or B | Heavy Timber | A or B |
The difference in A or B is the level of fire resistance construction rating.
Types 1 and 2 (602.2)
Types 1 and 2 construction are those types of construction in which the building elements listed in Table 601 are of noncombustible material.
Type 3 (602.3)
Type 3 construction is that type of construction in which the exterior walls are of noncombustible materials and the interior building elements are of any material permitted by this code. Fire-retardant treated wood framing complying with Section 2303.21 shall be permitted within exterior wall assemblies of a 2-hour rating or less.
Type 4 (602.4)
Type 4 construction (heavy timber, HT) is that type of construction in which the exterior walls are of noncombustible materials and the interior building elements are of solid or laminated wood without concealed spaces. The details of Type 4 construction shall comply with the provisions of this section. Fire-retardant treated wood framing complying with Section 2303.2 shall be permitted within exterior wall assemblies with a 2-hour rating or less.
Type 5 (602.5)
Type 5 is construction is that type of construction in which the structural elements, exterior walls and interior walls are of any materials permitted by this code.
For more information regarding Construction Types, see Chapter 6 of the North Carolina State Building Code OR call 980-314-CODE(2633) and follow the prompts for technical assistance to speak with one of our staff.