In construction, R-Value measures what aspect of materials?

R-Value is a metric that specifically measures thermal resistance, which quantifies how well a building material resists the flow of heat. The higher the R-Value, the better the material is at insulating and preventing heat transfer, meaning it contributes to maintaining a stable indoor temperature by slowing down the rate at which heat escapes or enters a building. This makes it a critical factor in energy efficiency for construction and building design.

While thermal conductance measures how easily heat can pass through a material (which is the inverse of thermal resistance), R-Value focuses squarely on the resistance aspect. Additionally, R-Value does not relate to structural strength or cost-effectiveness; these are separate characteristics that do not impact the thermal insulating capabilities of a material. Thus, the definition and application of R-Value distinctly align with the measurement of thermal resistance.