What Are R-Values for Construction Materials and How Do They Work?
R-value is the measure of a material’s resistance to heat flow, with higher numbers indicating better insulating performance. For every inch of thickness, materials like closed-cell spray foam can achieve R-6 to R-7, while fiberglass batts typically deliver R-3 to R-4, and rigid foam boards fall somewhere in between.
Understanding R-values isn’t just about meeting code requirements. It’s about making informed decisions that affect energy performance, long-term operating costs, and occupant comfort across the building’s lifespan. In 2026, as energy codes tighten and owners demand greater efficiency from their …









