Depends on where you live. In my country there are basically 2 classes: social housing and free market. Which one your home is is based on one thing: the rent you paid when you initially started living there. For each year, a threshold is set for social housing. Anything that is rented out under that threshold in that year will be considered social housing for however long the tenants stay there. Everything above it is free market.

For social housing, there is a point system that determines the maximum rent. Points are awarded based on the house itself. For example: each bedroom adds certain number of points, same for bathrooms and other features. Once you have the total number of points, you can look up the maximum rent in a table.

For both social and free market properties, there is a maximum annual rent increase.