[en] Based on the relationship between charge dimensionality and singular field behavior, it is proven that in a volumetric description of a volume current carrying topology, half rooftops of different binary hierarchical level are allowed without introducing numerical difficulties. This opens the possibility to use a very efficient multi-level hierarchical meshing scheme in a Volumetric Method of Moments (MoM) algorithm. The new meshing scheme is validated by numerical calculations and experiments. It paves the way towards a much more efficient use of MoM in the description of arbitrarily shaped nano-structures at IR and optical frequencies.