 In the 1860s, the population of Berlin was growing rapidly with the influx of around 50,000 people a year, creating a large administrative burden. When construction began on the Rotes Rathaus, the city had around half a million inhabitants, but this grew to 800,000 by the time of its completion in 1869. By the 1880s, the city had offices in ten additional buildings near the Rotes Rathaus and since it could not be extended, it was clear that a second administration building was required.
