As governments continue to impose more and higher energetic requirements for buildings, they also need better assessment-tools to take into account as many parameters as possible. This results in continuous developments of new calculation methods and softwares, where a balance has to be found between practicality and accuracy. To answer this problem, specifically with regard to the thermal bridges, the three Belgian regions developed a new and common pragmatic approach for assessing thermal bridges, confronting them either to simple basic rules of thumb or to maximal heat transmission coefficients, depending on the type of junction. While thermal bridges that don’t meet the requirements are sanctioned, thermal bridges that perform better can be taken into account to lower the calculated heat-losses. For this project, several very common thermal bridges were selected. Sensitivity analyse are carried out for the different parameters, such as dimensions and thermal conductivity of the components. The calculated heat transfer coefficients are confronted with the boundary-(‘limit-’)values and the default-values of the new methodology. Nevertheless, these analyses weren’t meant as a test for the methodology. They aim at allowing designers to quickly assess their common building details to the new regulation, without having to do preliminary numerical simulations of each individual thermal bridge. They also help them to better understand the correlations between the parameters of the building detail and the resulting heat transmission coefficients. The challenge that rose, was to summarize the results in pragmatic, straight-forward formats.