Thank you for the feedback. I just had the issue as well, although the terrace did not play a role here. I find it overall unfair that the costs for sewer construction are calculated based on the floor area including the basement. How does the size of the building relate to the amount of wastewater that will be discharged? Why is this not financed based on actual water consumption or discharge? In our town, the fee is 20€/m². That means for 80m² floor area with basement, the sewer construction fees amount to 4,800€. This is only for the wastewater; in addition, there is 2.5€/m² of land area for surface water and 3.5€/m³ for the water connection.