R-value is a measure of how well a two-dimensional barrier, such as a layer of insulation, a window, or a complete wall or ceiling, resists the conductive flow of heat). It is a rating system used to grade insulation products or a materials insulating properties. The higher the R-value, the more resistance a material has to heat flow, or temperature conduction. R-value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the warmer surface and colder surface of a barrier under steady-state conditions). R-values are additive for layers of materials, and the higher the R-value, the better the performance).

Insulation R-values vary based on the type, thickness, and density of the insulation material. Typically, a higher insulation R rating means better climate control and better energy efficiency for your home. The R-value your insulation needs depends on your local climate. The recommended home insulation R-values are specified by ENERGY STAR.

It is important to note that the material the insulation is made from will change the R-value as well. Radiant barriers and vapor barriers are not rated by R-values.

In summary, R-value is a measure of how well a material resists the conductive flow of heat, and it is used to grade insulation products or a materials insulating properties. The higher the R-value, the better the performance. Insulation R-values vary based on the type, thickness, and density of the insulation material, and the recommended home insulation R-values depend on your local climate.