About Us +
Researchers in the Building Technology & Urban Systems Division (BTUS) at Lawrence Berkeley National Laboratory develop data and technologies that increase energy efficiency and improve the health, safety and comfort of building occupants, in the United States and worldwide.

We work closely with industry partners, academics and government officials to achieve these goals, and share our research widely
Research +
We are at the forefront of cutting-edge research that redefines building technology and explores all areas of urban systems.

We have been leaders for decades in developing energy-efficient windows, improving indoor air quality, coming up with new ideas to fix the nation's electricity grid, and so much more.

Visit our research areas at the right to find out more.
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Publications +
Enjoy presentations from Building Technology & Urban systems research experts on a wide variety of topics in the areas of building energy efficiency, the electricity grid and how it relates to buildings and much more.
- Presentations
News
Tools & Guides +
Explore our tools, guidebooks and software and download for free.

We offer a variety of technologies designed to simulate and model real-world circumstances to assist in energy-saving programs and help building owners build better buildings. These tools can help calculate performance of building systems like windows and shades, help consumers and builders pick the best windows for a variety of applications and much more.

Publications: Solar Control:Modeling Optically Complex Fenestration Systems

Publications By Research Area

2022

Ward, Gregory J., David Geisler-Moroder, Eleanor S. Lee, Jacob C. Jonsson, and Taoning Wang."Daylight Simulation Workflows Incorporating Measured Bidirectional Scattering Distribution Functions."Energy and Building 259 (2022).

2021

Wang, Taoning, Gregory J. Ward, and Eleanor S. Lee."A Python Library for Radiance Matrix-based Simulation Control and EnergyPlus Integration."IBPSA Building Simulation 2021 (2021).

2013

Klems, Joseph H.."Complex Fenestration Calculation Module."EnergyPlus Engineering Reference (2013).

2011

Nouidui, Thierry Stephane, Andrew McNeil, Christian Kohler, Brian E. Coffey, and Eleanor S. Lee."Modeling solar heat gains of complex fenestration systems using bidirectional scattering distribution functions." (2011).

2000

Klems, Joseph H.."Solar Heat Gain Through Fenestrations Containing Shading: Procedures for Estimating Performace from Minimal Data." (2000).

1996

Klems, Joseph H., and Jeffrey L. Warner."Solar Heat Gain Coefficient of Complex Fenestrations with a Venetian Blind for Differing Slat Tilt Angles."ASHRAE Symposium 103, Part 1 (1996).

1995

Klems, Joseph H., Jeffrey L. Warner, and Guy O. Kelley."A Comparison Between Calculated and Measured SHGC For Complex Fenestration Systems."ASHRAE Transactions 102, Part 1 (1995).

Klems, Joseph H., and Guy O. Kelley."Calorimetric Measurements of Inward-Flowing Fraction for Complex Glazing and Shading Systems."ASHRAE Transactions 102, Part 1 (1995).

Klems, Joseph H., and Jeffrey L. Warner."Measurement of Bidirectional Optical Properties of Complex Shading Devices."ASHRAE Transactions 101, Part 1 (1995).

1993

Klems, Joseph H.."A New Method for Predicting the Solar Heat Gain of Complex Fenestration Systems I. Overview and Derivation of the Matrix Layer Calculation."ASHRAE Transactions 100, Part 1 (1993).

Klems, Joseph H.."A New Method for Predicting the Solar Heat Gain of Complex Fenestration Systems II. Detailed Description of the Matrix Layer Calculation."ASHRAE Transactions 100.1 (1993).