The objective of this two days workshop is to furnish guidance on the appropriate application of Building Performance Simulation (BPS), to promote good practice and to offer reference material to support practicing environmental engineers and architects. The workshop will cover the basics of using DesignBuilder simulation tool with an emphasis on application and case studies. The workshop also emphasizes the importance of simulation for decision support and code compliance for new and existing buildings. The workshop is aimed at new and less experienced DesignBuilder simulation users. The workshop introduces users to DesignBuilder and helps them in to understand the tool mechanics and be able to model and run simulations. The course will cover the data input, output and post processing issues.