The VenSpec-H instrument is part of the EnVision M5 mission payload which has been selected by ESA to enter Phase A in January 2019 for a potential mission selection in 2021. EnVision is a medium class mission to determine the nature and current state of geological activity on Venus, and its relationship with the atmosphere, to understand how Venus and Earth could have evolved so differently. VenSpec-H will target different molecular species in nadir viewing geometry, as to better characterize the surface-atmosphere interaction. The scientific preparation and the preliminary design will be presented.