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Simulated versus Measured Energy Performance of the NIST Net Zero Energy Residential Test Facility Design



Joshua D. Kneifel, William V. Payne, Tania Ullah, Lisa C. Ng


The National Institute of Standards and Technology (NIST) received funding through the American Recovery and Reinvestment Act (ARRA) to construct a Net Zero Energy Residential Test Facility (NZERTF). The initial goal of the NZERTF is to demonstrate that a net-zero energy residential design can “look and feel” like a typical home in the Gaithersburg area. The demonstration phase of the project was from July 2013 through June 2014, during which it successfully demonstrated that the house performed at “net zero,” or produced as much electricity as it consumed over the entire year. The purpose of this report is twofold. The first is to compare the pre-demonstration phase whole building energy simulation to the measured performance of the NZERTF during the demonstration phase, which will identify where the measured performance deviates from the simulated performance of the house in its design state. These variations may be due to incorrect simulation assumptions (e.g., incorrect efficiency parameters) or faulty demonstration phase operation control of the NZERTF itself (e.g., equipment failures). The components of the NZERTF for which the simulation and measured performance vary the most can be used as a “lessons learned” guide for other researchers to consider in other low-energy house simulation efforts. The second purpose is to adjust the pre-demonstration phase simulation specifications to better represent the actual performance of the NZERTF during the demonstration phase. The adjustments will lead to the development of a validated simulation model that can be used for analysis of “what-if” scenarios, such as alternative configurations of equipment, occupancy activity/behavior, building envelope options, or sensitivity analysis. There is significant variation between the pre-demonstration phase simulation results and measured demonstration phase performance. First, the initial simulation assumptions were incorrect due to a lack of information on the specifications
Special Publication (NIST SP) - 1182
Report Number


Net zero energy construction, energy efficiency, residential building, whole building energy simulation


Kneifel, J. , Payne, W. , Ullah, T. and Ng, L. (2015), Simulated versus Measured Energy Performance of the NIST Net Zero Energy Residential Test Facility Design, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed April 14, 2024)
Created March 30, 2015, Updated November 10, 2018