When you buy an apartment, you are actually buying a 'home in co-ownership'. There will therefore be a number of rules that you will have to observe in order to ensure that you can live together in a respectful manner.
In order to establish clear rules, internal regulations are often drawn up. This will set out a number of household rules that residents of the same building must abide by. This will often involve rules relating to safety and cleanliness, e.g. on the use of the bicycle shed, the placement of garbage bags, the use of a laundry rack on the balcony, smoking in the building, etc.... The rules will of course vary from building to building (as each building is different).
Is it legally required?
It is not required by law to draw up internal rules of procedure and there are no specific rules regarding their content. It is only necessary to ensure that certain rules do not contradict the elements contained in the basis deed or the rules of co-ownership. If there are rules, they must be respected by the owners/occupants.
Does my tenant also have to comply with them?
If you rent out your apartment, you are obliged to inform your tenant of the internal rules since the tenant must comply with them (he/she is, after all, occupying the apartment). Usually this is included in the lease agreement so that at the beginning of the contract the tenant is aware of the housekeeping rules and the fact that he/she must comply with them.
The rules are sometimes also included in the basic deed or are often drawn up during the general meeting. Elements can then also be added or modified in consultation with the trustee.