This report, one of the deliverables for the IEA Annex 67 on Energy Flexible Buildings, provides a comprehensive review of control methodologies to provide energy flexibility in buildings. The reviewed methodologies range from classical rule-based control to model predictive control and reinforcement learning based control. The objective of the report is to help practitioners formulate their optimal control problems according to the framework which best suits their problem. ispartof: Review of applied and tested control possibilities for energy flexibility in buildings status: Published online