A/HRC/34/51/Add.2 91. Existing social housing stock should be kept in good repair, in keeping with the characteristics of adequate housing as defined by the Committee on Economic, Social and Cultural Rights in its general comment No. 4 (1991). A system must be in place to ensure the efficient allocation of vacant units in social housing, in the light of the long waiting lists. 92. Long-term rentals should be promoted as an alternative means of access to affordable housing. Short-term rentals targeting the tourist sector should be regulated, and their impact on affordability properly assessed with a view to combating practices that result in the exclusion of long-term residents of specific neighbourhoods. 93. Housing programmes such as those proposed by housing cooperatives for new housing and urban upgrading, or those emerging from participatory budgeting, strengthen real and effective participation of the population directly concerned in the design and implementation of housing policies, and should therefore be encouraged. Collective and cooperative forms of ownership and use of land and housing should also be promoted. 94. Serious consideration should be given to the identification of vacant land or, when possible, to the expropriation of land for public use, so as to ensure security of tenure for “self-built” neighbourhoods and to enhance the availability of land for social housing. 95. National and subnational authorities should enhance the use of maximum available resources in the housing sector, including by ensuring that revenues from policies such as golden visas, property taxes or tourism taxes are invested with the aim of providing access and truly affordable housing to the most marginalized sectors of society. 20