The built environment accounts for approximately 30-40% of the total energy consumption in the Netherlands and Germany (RVO, 2015). The INTERREG project Cleantech Energy Crossing therefore aims to facilitate the energy transition in this area by promoting cross-border collaboration. Through the realization of various innovations and new technological products, this project wants to make an important contribution in achieving the climate targets of the Netherlands (-20% CO2 emissions to 2020) and North Rhine-Westphalia (-25% CO2 emissions to 2020).