In the context of construction, the 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.

What is the best R value for insulation?

Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces. See the Department of Energy's (DOE) ranges for recommended levels of insulation below.

Which is better R13 or R19 insulation?

Inside your home, the warmer air is higher pressure air, and wants to move, or transfer to lower pressure, cooler air outside. Insulation in your walls and ceilings slows down this heat transfer. ... So R19 is better insulation than R13, and R30 is better than R19. The larger the R value, the better the insulation value.