EBC Annex 43 Testing and Validation of Building Energy Simulation Tools


Status: Completed (2003-2007)

Operating Agent: (in conjunction with IEA Solar Heating and Cooling Task 34)
Ron Judkoff, Buildings & Thermal Systems Center, National Renewable Energy Lab (NREL),
1617 Cole Blvd., Golden, CO 80401, USA
Tel: +1 303 384 7520
Fax: +1 303 384 7540
Email: ron_judkoff[at]nrel.gov

Website: http://task34.iea-shc.org/



Building energy analysis software is increasingly used in the design and planning of buildings. The goal of this project was to undertake pre-normative research to develop a comprehensive and integrated suite of building energy analysis tool tests involving analytical, comparative, and empirical methods. These methods will provide for quality assurance of the software, and some of the methods will be enacted by codes and standards bodies to certify software used for showing compliance to building energy standards. This goal was pursued with the following objectives in mind:


To create and make widely available a comprehensive and integrated suite of IEA Building Energy Simulation Test (BESTEST) cases for evaluating, diagnosing, and correcting building energy simulation software. Tests addressed modelling of the building thermal fabric and building mechanical equipment systems in the context of solar and low energy buildings.

To maintain and expand as appropriate analytical solutions for building energy analysis tool evaluation.
To create and make widely available high quality empirical validation data sets, including detailed and unambiguous documentation of the input data required for validating software, for a selected number of representative design conditions.


There were two research areas: comparative tests, and empirical validation.

Participating Countries: Australia, Belgium, Canada, Denmark, France, Germany, Ireland, Japan, the Netherlands, Sweden, Switzerland, the United Kingdom, and the United States


Ground Coupling Comparative Tests

Final Report: IEA BESTEST In-Depth Diagnostic Cases for Ground Coupled Heat Transfer Related to Slab-on-Grade Construction
Joel Neymark and Ron Judkoff, 2008 Download
Documents a set of idealised in-depth diagnostic test cases for use in validating ground coupled floor slab heat transfer models. these test cases represent an extension to IEA BESTEST 1 which originally focused on testing and validation of building thermal fabric models, but addressed only cursorly the modelling of heat transfer between the building and the ground.

Multi-Zone and Air Flow Comparative Tests

Final Report: IEA BESTEST Multi-Zone Non-Airflow In-Depth Cases: MZ320-MZ360
Joel Neymark and Ron Judkoff, 2014
Download (Accompanying files are also available.)

Shading/Daylighting/Load Interaction Empirical Validation Tests

Final Report: Empirical Validations of Shading/Daylighting/Load Interactions in Building Energy Simulation Tools
Peter Loutzenhiser, Greg Maxwell, Heinrich Manz, 2007 Download
These studies are some of the most detailed empirical validations of solar gain models implemented in building energy simulation programs. The purpose of this project was to create data sets for use when evaluating the accuracies of models for glazing units and windows with and without shading devices. Program outputs were compared with experiments performed at an outdoor test cell in Switzerland and a facility in the United States. The authors’ intention is that the data are widely used by program developers and modelers for future validation efforts.

(Modellers' Reports, ERS Daylighting Experiments and EMPA Exercises are also available.)

Mechanical Equipment and Control Strategies Comparative and Empirical Validation Tests

Final Report: Mechanical Equipment & Control for a Chilled Water and a Hot Water System
Clemens Felsmann, 2009

Simulation of HVAC Components with the Help of an Equation Solver
Lemort, Rodriguez and Lebrun, 2008 Download
Presents models of different HVAC mechanical equipment components. These models have been developed with the help of EES (Engineering Equation Solver). This modelling tool allows an equation-based approach: each component is modelled by a set of equations which describe the main physical processes/peculiarities inherent to the component.

(Chilled Water System Tests and Hot Water System Tests are also available.)

Double Facade Building Comparative and Empirical Validation Tests

Final Report: Double Skin Facades: A Literature Review
Harris Poirazis, Department of Architecture and Built Environment, Division of Energy and Building Design, Lund University, Lund Institute of Technology, Lund, 2006

Final Report: Empirical Validation of Building Simulation Software: Modelling of Double Facades
O. Kalyanova, P. Heiselberg, Aalborg University, 2009

Final Task Management Report

Annex 43/Task 34 Final Task Management Report - Testing and Validation of Building Energy Simulation Tools
Ron Judkoff, 2008