Berlin is growing and developing constantly. So the rental prices keep growing. In the past 2-3 years round about 9%.
Like in the most big cities the inner-city of Berlin is asked most. This is also represented in the rent index. Because of Berlins different agglomerations the popular living zones spread over the whole inner-city. Due to its central location the district of Friedrichshain-Kreuzberg, Mitte and Charlottenburg-Wilmersdorf are the most preferred areas. The rental prices are in dependence to the popularity, but in that case the reaction on the huge demand are newly built flats. The price area for rent goes from 13€ up to 18€ per square meter.
The indoor environment quality in the capitol of Germany has its own price, which will only keep getting higher in the upcoming time.