To ensure that the housing market functions properly, it is therefore desirable to create a larger mid-segment rental market. Since 1 July 2017, the Spatial Planning Decree has expanded the scope of the possibilities for municipalities to set requirements in zoning plans. This means that in addition to the existing categories in a zoning plan, which are subsidised rental houses, subsidised owner-occupied houses and private commissioning, municipalities now have the option of adding liberalised houses for the mid-segment rental market as a separate category. The requirements regarding types of housing concern percentages relating to the plan or project area. This means that a specified minimum percentage of the new houses built in the area covered by the zoning plan must be liberalised houses for the mid-segment rental market. This allows municipalities to use public law instruments to gear housing towards mid-segment rental houses with a rent that exceeds the rent-control ceiling. These are houses with an initial rent of a minimum of €710.68 (price level 2016), which is the rent-control ceiling. The initial rent is the rent (excluding service charges and advances on mains services) at the start of the lease. The maximum initial rent, which is set by municipalities in a regulation, is indexed every year on the basis of, for example, the consumer price index published by Statistics Netherlands (CBS).

In short, by giving municipalities the option to include liberalised houses for the mid-segment rental market in zoning plans, municipalities have more influence on the composition of the housing stock in their municipality. They can also ban a particular type of residential or other use, which ensures that the stock is not diminished. Since municipalities can apply this provision to each subarea in a zoning plan, they can gear the market towards a balanced division between various categories of housing in the case of, for example, an upcoming area development. In the not too distant future when the new Environment and Planning Act (Omgevingswet) comes into force, this special legal basis will no longer be necessary as government authorities will have even more flexibility and freedom to manage the quality of the living environment and such rules can also be laid down in general municipal rules (such as the Environment Plan).

This public law instrument gives municipalities the possibility to impose requirements regarding rental prices, but this does not mean that the houses can only be rented by people with a "middle income". Although this can be used as a selection criterion upon commencement of a lease, it will not prevent people with a higher income from living in such houses. If a tenant’s income increases, the landlord has no legal basis to terminate the lease. If the government wants to do something about this, it will have to make tenancy law even more flexible.