Although the neutrino mass-flavor PMNS mixing matrix and the splittings among masses have been adequately assessed, the absolute mass scale is yet unknown. Further, the discovery of Higgs boson opens new pathways for theoretical investigations on the origin of the neutrino masses. Therefore, beside the intrinsic merit, direct mass searches are becoming more and more intriguing also for the impact on these models. Laboratory measurements with beta or electron capture decaying isotopes permit model-independent access to the mass, but are technologically very challenging. However, after several years of efforts, the present technology achievements allow the design of large scale apparatus with high spectral resolution needed for probing the sub- eV mass range. Here we will discuss about the project HOLMES on Ho-163 EC decay, that has been recently approved by the European Research Council and will be performed in the facilities of the Italian Institute of Nuclear Physics (INFN). The seminar will cover the present status of the calorimetric methods for neutrino mass measurement, the interplay between the R&D for Re-187 and Ho-163 calorimetric spectroscopy, and the perspective of HOLMES in a possible large collaborative effort.