Long before he moved into the historic building, Dutch architect Felix Claus admired 51 rue Raynouard, an apartment block in the Passy district of Paris designed and built in 1932 by Auguste Perret. One of the seminal architects of the 20th century, Perret is renowned for high-profile commissions like the Théâtre des Champs-Élysées in Paris and the post–Second World War rebuild of Le Havre, and for his pioneering use of reinforced concrete. He constructed 51 rue Raynouard to house the design firm he ran with his two brothers and created a 1,830-square-foot apartment on the seventh floor for himself and his wife. Here, the apartment’s balcony offers  an impressive view of rue Raynouard.  Photo 1 of 11 in 10 Dreamy Parisian Homes from Modern High-Design Pied-à-Terre in Paris