Building Information Modeling (BIM) for optimizing the total lifecycle cost of buildings is a challenge even
today. Inadequate software interoperability, high costs as a result of the fragmented nature of the building industry, lack of
standardization, inconsistent technology adoption among stakeholders are just some of the obstacles that architects and
engineers face. However, optimization requires a structured procedure that enables continuous changes in design variables
and assessment on energy consumption. A holistic building design and construction are already introduced in Europe
through the energy performance of buildings directive (EPBD). The requirements have been strengthened by the EPBD
recast for achieving cost optimal building designs for the life cycle of the building, moving towards nearly zero energy
buildings by the end of the decade. BIM and intelligent services could play a crucial role in these efforts with improved
visualization and productivity due to easy retrieval of information, increased coordination of data and exchange of information,
all leading to a reduced cost for the design of energy efficient buildings. An ongoing European research project
aims to contribute to these needs by developing a Virtual Energy Laboratory that will support building energy performance
simulations taking into account the stochastic nature of input parameters and processes. This will be supported by information
communication technology features utilizing the necessary computational power through cloud computing. This
paper presents an overview of the ongoing efforts and focuses on results for assessing the impact of different input
weather and climate data that are pertinent in building load and energy performance calculations.