The aim of the communication is to precise why the issue of empty housing is a serious problem in the main cities of Wallonia (Belgium) and why an increasing number of urban owners are neglecting their property assets. This reflection is based on three surveys where various kinds of owners have been questioned: a first group of people representative of all the owners active on the residential locative market, a second group based on a sample of residential empty buildings and a third group based on a sample of commercial buildings with empty floors. The surveys analysis demonstrates that the empty housing situation is related to problems deeply rooted in the Belgian society. In this country, council housing for rent is scarce and home-ownership has always been the pillar of the housing policy. In the last decades, this persistent policy has contributed to a decrease of the profitability of the rental investments as it has economically contracted the locative market to the weakest populations. The widening of the local housing markets and the intense residential suburbanisation are other key explanations of the empty housing problems. Indeed, in a context of demographic stagnation, such evolutions have generated urban depopulation as well as investment apprehensions for the central urban fabrics.