The District Energy Simulation Test (DESTEST) is a series of common exercises about modelling building stocks and district heating networks aiming at testing, benchmarking and verifying different urban-scale energy system simulation tools. For each common exercise, participants are modelling a case with well-defined characteristics, grid topology and boundary conditions. The DESTEST allows participants to discuss common mistakes and pitfalls and define guidelines from the experience and feedback. These common exercises can also be used for training purposes. This article discusses the development process of these common modelling exercises and presents the main lessons learnt during the creation of the DESTEST.