To limit thermal bridging between materials that come into contact with steel framing and to reduce the quantity of steel that must be utilized in a steel framing system.
CALGreen Code Section A5.213.1: Steel framing.
Design steel framing for maximum energy efficiency. Techniques for avoiding thermal bridging in the envelope include:
1. Exterior rigid insulation;
2. Punching large holes in the stud web without affecting the structural integrity of the stud;
3. Spacing the studs as far as possible while maintaining the structural integrity of the structure; and
4. Detailed design of intersections of wall openings and building intersections of floors, walls and roofs.
Intent:
The intent of this provision is to provide means to reduce the thermal bridging of materials in contact with steel framing and to conserve the amount of steel used in a steel framing system. Structural standards for building framing, and for steel in particular, are found in CCR, Title 24, Part 2, the California Building Code. Building energy efficiency standards are found in Part 6, the California Energy Code.
Compliance Method:
Within structural parameters of the California Building Code and energy efficiency standards of the California Energy Code, specify material-efficient steel framing for those projects framed in steel. Provide framing, assembly and intersections details, and material specifications in the construction documents. Where feasible, install exterior rigid insulation to reduce the transmission of heat through assemblies. It is possible that rigid insulation and/or exterior wall cladding cannot span widely spaced framing members, so a choice of alternative techniques may need to be made.
Enforcement:
Plan intake: The plan reviewer should review the construction documents for energy efficiency measures taken with the steel framing system and for compliance with Parts 2 and 6 of Title 24. On-site enforcement: The inspector should verify that the energy efficiency measures shown in the construction documents are included on the project. A framing inspection may reveal any steel material conservation measures, and an additional inspection to examine envelope and detailing may be necessary.
(Excerpted from ‘Guide to the 2022 California Green Building Standards Code Nonresidential’ – Appendix A5)
