A five-member panel of “outsiders” has recently examined the software architecture of DOE's EnergyPlus building energy simulation program with respect to robustness, computational efficiency, extensibility, maintainability, and usability.  Two members of the panel will informally present conclusions from that study and then open the floor for discussion of the panel’s recommendations. Barnaby is Vice-President of Research at software developer Wrightsoft Corporation in Lexington, MA and is Chair of the Review Panel.  He has a B.A. in Engineering and Applied Physics from Harvard University and a M.Arch. from the University of California, Berkeley.  He co-founded Berkeley Solar Group in 1974 and was  Software Development Leader at XENERGY before joining Wrightsoft, where he leads loads and energy calculation development.  Recent work includes interoperability and EnergyPlus interface implementation.  He is active in ASHRAE, IBPSA, and IBPSA-USA and is a former Chair of ASHRAE TC4.7 Energy Calculations. Sonderegger is Director and Engineering Advisor at Itrón, Inc. in Oakland, CA.  He has a master's degree in Physics from ETH in Zürich, Switzerland and a Ph.D. in Mechanical Engineering from Princeton University.  He was a Staff Scientist and Deputy Program Leader at LBNL before entering the private sector.  He was Chief Application Scientist at Silicon Energy before assuming his current position at Itrón.  He has 25 experience in Building Energy Analysis and Energy Simulation, 10 years experience in large database systems used for meter data management systems and is a former Chair of ASHRAE TC4.7 Energy Calculations.