Unfortunately, just paying the rent for your property is not enough. You also need gas, water, and electricity (GWE). Sometimes, the rent will include these costs, but this is not always the case. Every year, the Nibud (original source) calculates the average prices for GWE for all different kinds of households. For a regular apartment, the price is between 100 and 140 euros each month. So, before you will rent a room, an apartment or other property, always check if the rent includes or excludes the costs for GWE.