Considering the high and unpredictable price of lumber in today's market, steel seems a logical alternative to wood construction. On the other hand, a major disadvantage is that steel is a very good conductor of heat into and out of the building. A poorly designed steel framing system will increase heating and cooling costs considerably. The California Energy Commission has established energy efficiency building standards that require that steel-framed systems meet a minimum thermal efficiency requirement. This requires construction technologies different from traditional wood frame construction.
Many designers erroneously assume steel and wood studs are thermally equivalent.
Noting that the steel studs are thin compared to wood studs, some argue that the difference in thickness is more than enough to offset the conductive characteristic of steel. Despite their thin web, however, steel studs are much more conductive than wood studs. The heat is conducted between the flanges via a thin web as long as the depth of a wood stud. Thermal bridging reduces the cavity insulation R-value by about 50 percent. To make up for this efficiency loss, a designer could use larger studs and add more insulation, but thermal bridging will substantially diminish the benefit gained by additional insulation.