The IEA has created a number of procedures for testing and validating building energy simulation programs. This work was the product of IEA Solar Heating and Cooling (SHC) Programme Task 22, and an earlier collaboration of IEA SHC Task 12 and Energy Conservation in Buildings and Community Systems (ECBCS) Annex 21.

These procedures are now being used by software developers to diagnose and correct errors in building energy simulation computer programs throughout the world. Some of these procedures have been, or are in the process of being, adopted by international codes and standards organizations for certification of software. ANSI/ASHRAE Standard 140 codified the original IEA Building Energy Simulation Test (BESTEST) as a standard method of test for software, and the European Committee for Standardization (CEN) used BESTEST to check their reference cooling load and cooling energy calculation methods based on the requirements of prEN 13791 and 13792.

The recently issued Energy Performance Directive (EPD) of the European Union emphasizes performance-based standards and requires certification of software used to show compliance with energy performance standards (normes). This is a very positive development because with true performance-based normes, renewable energy technologies and innovative energy efficiency measures in buildings are encouraged and not constrained by prescriptive requirements. However, the modeling of innovative low energy buildings is challenging, and existing methods for testing such software are not yet comprehensive enough. In this context the work proposed for this task may be thought of as “pre-normative” research. For example, at the April 2003 Task Definition Workshop in Delft, Netherlands, participants established that the reference calculation methods under development by CEN will work for the vast majority of conventional buildings, but will not be adequate for innovative low energy buildings. Therefore, the work proposed under this Task is meant to ensure that the software for modeling innovative low energy buildings can be tested, validated, and certified in accordance with the needs of those organizations responsible for promulgating and enforcing building codes and standards