  Habitable zone dust levels are a key unknown that must be understood to
ensure the success of future space missions to image Earth analogues around
nearby stars. Current detection limits are several orders of magnitude above
the level of the Solar System's Zodiacal cloud, so characterisation of the
brightness distribution of exo-zodi down to much fainter levels is needed. To
this end, the large Binocular Telescope Interferometer (LBTI) will detect
thermal emission from habitable zone exo-zodi a few times brighter than Solar
System levels. Here we present a modelling framework for interpreting LBTI
observations, which yields dust levels from detections and upper limits that
are then converted into predictions and upper limits for the scattered light
surface brightness. We apply this model to the HOSTS survey sample of nearby
stars; assuming a null depth uncertainty of 10$^{-4}$ the LBTI will be
sensitive to dust a few times above the Solar System level around Sun-like
stars, and to even lower dust levels for more massive stars.
