Glass Glossary


Last Updated: November 23, 2023

R-value is a metric that measures the thermal resistance of a material, indicating its ability to resist heat flow. It’s expressed as ft²·°F·hr/BTU, where a higher R-value denotes superior insulating capabilities, contributing to increased energy efficiency and decreased heating and cooling costs.

R-value is invaluable when evaluating the energy efficiency of different building materials, including window and door products. With higher R-values, homeowners and builders can achieve enhanced thermal insulation, minimizing heat loss in winter and heat gain in summer. This leads to a more comfortable living environment and substantial energy savings. Moreover, windows and doors with a high R-value support sustainable building practices by reducing the overall carbon footprint of a building.