 The engineer Ángel Chueca Sainz was in charge of calculating the new building's metal structures, Chueca Sainz was the father of the distinguished architect Fernando Chueca Goitia.The construction started quickly and the people gave it the humorous name ‘"Nuestra Señora de las Comunicaciones’" (Our Lady of Communications) because of its monumental character and size.In 1916 it first opened its doors to the Public Postal Savings Bank ("Caja Postal de Ahorros)" despite the building not being completed until 1918.