About Us

The broad vision of the Windows and Envelope Materials Group is to transform windows from a net energy penalty to a net energy supplier in new and existing buildings, while improving occupant comfort and amenity.

About Us

The Windows and Envelope Materials Group, part of the Building Technology and Urban Systems Division, conducts the low-energy, high-performance building façade solutions work at Lawrence Berkeley National Laboratory. The group develops energy-efficient window systems and studies advanced daylighting designs that allow the use of natural light in place of electric lighting.

Glazing and façade systems have very large impacts on all aspects of commercial building performance. They directly influence peak heating and cooling loads, and indirectly influence lighting loads when daylighting is considered. In addition to being a major determinant of annual energy use, they can have significant impacts on peak cooling system sizing, electric load shape, and peak electric demand. Because façades are prominent architectural and design elements, and because they influence occupant preference, satisfaction, comfort, and health, the design optimization challenge is more complex than with many other building systems.

Since 1992, the U.S. Department of Energy has partnered with the California Energy Commission Public Interest Energy Research (PIER) Program (now the Electric Program Investment Charge, or EPIC, program) to support the research, development, and demonstration of advanced integrated window and daylighting technologies and systems that are not adequately provided for by competitive and regulated energy markets. This collaborative research continues to be committed to serving the needs of industry, helping stakeholders to understand how innovative solutions fit within the broad and complex context of building applications.

The broad vision of the program is to convert windows from their current role as a net energy penalty to a net energy supplier in both new and existing buildings while improving comfort and amenity. Since performance data are key to informed decision making, innovative technologies are evaluated using simulations, laboratory studies, field tests and in demonstration buildings with industry partners. Developing and validating software to both derive and evaluate technologies is an integral part of the research. Researchers investigate integrated façade solutions, determining impacts on both HVAC and lighting energy use, as well as comfort and indoor environmental quality.