05/08/2026
Individual material properties don’t equal high-performance wall assemblies.
Fiber-Reinforced Polymer (FRP) support systems are often positioned as the superior thermal solution, citing lower conductivity, reduced thermal bridging, and higher “thermal efficiency.” However, these comparisons are typically made at the material level, not the assembly level where real performance is determined.
Once evaluated as part of a complete wall system, additional variables come into play, many of which significantly influence overall thermal performance.
FRP girts reduce heat transfer through the material itself, but they often require more frequent attachment points due to strength limitations. This increases pe*******ons, each introducing an additional pathway for heat flow.
Thermally improved steel systems take a different approach. While steel has higher conductivity, systems like our THERMAZEE are engineered with features such as strategic punch-outs, thermal isolators, and engineered air gaps to disrupt the thermal path, resulting in substantial improvements in overall performance.
When evaluated at the assembly level, both systems perform exceptionally well, consistently meeting and often exceeding current energy code requirements at equal insulation thicknesses. For example, modeled U-factor values may fall around U ≈ 0.046 for FRP and U ≈ 0.052 for thermally improved steel, a difference of just 0.006. In a typical prescriptively designed commercial building, that translates to less than 0.2% of total annual energy cost.
It’s also worth stepping back and recognizing how far the industry has come. Not long ago, wall assemblies with U-factors of 0.075+ were standard practice. We’ve made major strides, but we’re now firmly in the territory of diminishing returns. Squeezing out incremental improvements in clear wall thermal performance delivers smaller and smaller gains in real-world building performance.
At this level, the question isn’t can we improve thermal performance further, it’s whether those marginal gains are meaningful enough to drive the decision when other factors are at play.
Considerations of drainage, structural reliability, fire performance, constructability, and cost efficiency often become equally, if not more, important. Optimizing performance isn’t about selecting a single material; it’s about evaluating the system as a whole.
If thermal performance is effectively comparable in practice, is the marginal gain worth giving up the broader advantages?
