The Otto Wulff was built in just two years, between 1912 and 1914, and until the inauguration of the Güemes Gallery it was the tallest building in Buenos Aires. Until June of last year, the façade of the Otto accumulated soot, dirt, smog and guano from pigeons and bats.
With hundreds of nebulizer spikes they sprayed the front with water, constantly, to loosen the dirt. And then, with neutral soap and brushes, they finished cleaning the stone-like coating.