Under the current income tax rules you can be renting out a room in your house. How does this work?
If you rent out a room in the house and the total annual rent is less than EUR 4.748 in 2014, the rent is not taxed. If you collect more rent, then the rent is only tax free if you sublet the room. So in a rental home a room is being rented.
You own the house and rent out a room
The situation is different when you own the house. If you own the house the tax free amount of rental income from a room in this house is EUR 4.748. If this amount is exceeded, then there is no tax free amount. In that case the part of the house you rent out is pro rata split. The WOZ value of the house you need to report is pro rata reduced. The same for the mortgage interest you deduct, that is pro rata reduced. Renting out a room in your home that you own exceeding the annual amount of EUR 4.748 can therefore have a significant impact.
The rental income is including utility costs, cleaning, furniture etc cannot exceed the maximum amount. This maximum amount is increased every year.