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Simulating Occupancy in The NIST Net-Zero Energy Residential Test Facility



Farhad Omar, Steven T. Bushby


The Net-Zero Energy Residential Test Facility (NZERTF), at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, is a research house that is comparable in size and aesthetic to the houses in the greater Washington DC metro area. The purpose of the NZERTF is to demonstrate the feasibility of achieving net zero energy over the course a year (i.e., energy generated using photovoltaic modules and solar hot water equals energy consumed). The lifestyle choices of the occupants can have a substantial effect on the overall energy consumption of the house. As a laboratory facility, a methodology was needed to simulate this occupants’ behavior. The occupancy in the NZERTF is emulated by a virtual family of four whose behavior and activities are based recommendations published by the U.S. Department of Energy. In order to attempt to realistically emulate the daily activities of the virtual family it is necessary to replicate their occupancy profiles, water usage, lighting usage, miscellaneous electric plug loads, cooking loads, appliances loads, and sensible and latent loads. This paper discusses the methodology, strategy, and hardware behind emulating the occupancy in the NZERTF.
Technical Note (NIST TN) - 1817
Report Number


Net zero energy house, net zero energy residential test facility, occupancy profile, occupancy schedule, occupancy emulation, daily occupancy emulation schedule


Omar, F. and Bushby, S. (2013), Simulating Occupancy in The NIST Net-Zero Energy Residential Test Facility, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 26, 2024)


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Created November 21, 2013, Updated November 10, 2018