The Basel region is one of the most seismically active regions in Switzerland. Already devastated by Nature in 1356, the city of Basel is now actively involved in assessing the seismic risk on its buildings in order to protect its patrimony and its population as effectively as possible. Through innovative assessment methods, researchers and scientists throughout Switzerland are working to effectively and accurately assess seismic risk through the three components that define it: hazard, exposure and vulnerability. It is this latter element that is addressed in this report. While the assessments carried out so far deal with the buildings one by one, an essential aspect of Basel's built environment is hidden in the row configurations of many buildings. Indeed, due to the desire to optimize space, many buildings are adjacent to each other, modifying thus their seismic behaviour. This document is therefore a first study of the vulnerability of building rows in order to reveal whether the effects of this particular configuration are beneficial or not. Thanks to epoch plans collected from the archives of the Canton of Basel-Stadt and dynamic simulations based on the Applied Element Method, the consequences on the vulnerability of two types of rows of masonry buildings are estimated. As a conclusion, the impact of introducing new fragility curves on the assessment of damage in the Iselin district makes it possible to highlight the effects of taking into account the row configuration of the buildings it contains.