Thermal bridges increase the building energy demand for heating and cooling. For well insulatedenvelopes and buildings with increased energy efficiency, the influence of thermal bridging on theenergy consumption is of major importance. Here the ratio between the thermal bridging effect and the overall thermal losses increases compared to low or medium insulated buildings and it is possible that the effect of thermal bridges on the energy demand compensates or even overtakes, for instance, the energy gain provided by thermal solar collectors for domestic hot water. The impact of thermal bridging on the energy consumption is even more pronounced in the case of building retrofit, where solving thermal bridges often is an issue, especially where external insulation is not applicable because of architectural constraints or not effective because of the presence of a lot of balconies.This paper is based on the work in a European project called ASIEPI (Assessment and Improvement of the EPBD Impact (for new buildings and building renovation), www.asiepi.eu). It presents three different issues in connection with thermal bridges:1. National requirements and calculation procedures (detailed and simplified) in the Member Statesparticipating in ASIEPI. In order to facilitate a correct comparison amongst MS regulations, theoverview is split per geographical and climatic area: Northern, Central and Southern Europe.2. Impact of thermal bridges on the energy performance of buildings. Studies that analyse theinfluence of detailed calculations of thermal bridges in comparison of neglecting the influence, butalso in comparison with default values for thermal bridges have been gathered for both summerand winter conditions.3. Thermal bridge atlases and software to calculate thermal bridge effects. An overview and acategorisation of available atlases and software products have been made.