When prices or rents are kept artificially low by regulations that basically means the market is rationed. The invisible hand of the market dictates that when prices drop, demand rises and supply drops. If the market was in equilibrium before (supply = demand) a forced price drop means future demand will exceed supply. Some of the demand will be disappointed.
Rationing occurs in real estate markets when the government for example sets a maximum rent for housing. In the Netherlands there is a points system that basically determines the maximum rent for smaller homes. This in practice means that, regardless of efforts of social housing corporations, the market cannot supply enough homes to fulfill demand. The consequence is that many people end up on waiting lists. For some properties in the strongest parts of the country the waiting list is longer than 10 years.
So, when by law real estate rents are kept artificially low this almost by definition leads to waiting lists. Instead of paying for reasonable housing in money, people have to pay in time on a waiting list; in the meantime live in a less desirable housing situation.