Lighting Power Density (LPD) is a lighting power requirement defined in North America by the American National Standards Institute (ANSI), American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), and the Illuminating Engineering Society of North America (IESNA) Lighting subcommittee.
The Oregon Department of Energy defines lighting power density as "The maximum allowable lighting density permitted by the code.
It is expressed in watts per square foot for a given occupancy/space type.
For example, ANSI/ASHRAE/IESNA Standard 90.1-2007 allows the Emergency Space of a hospital to be designed for 2.7 watts per square foot, but the Recovery areas of a hospital would be allowed 0.8 watts per square foot.
For example, ANSI/ASHRAE/IESNA Standard 90.1-2007 allows manufacturing facilities 1.3 watts per square foot, while parking garages are only allowed 0.3 watts per square foot.