Was born in 1693 in Vienna and was an austrian architect of the baroque, rococo and baroque classicism. Son of Johann Bernhard Fischer von Erlach, he continued some projects of his father and after his dead, he worked on many palaces, castles, and churches, as well as numerous monuments, gardens, tombs, and altars.He first developed his skills in his father's workshop. In 1711, he worked on several of his father's commissions and also helped complete the publication "Draft of a historical architecture"; whose four volumes inspired many later designs.
Until 1714, he received instruction in Vienna from his father's guest Gottfried William Leibniz. The two obtained a travel scholarship for Joseph Emanuel from Kaiser Karl VI. This led him in 1713/1714 to Italy.
From 1717-1719, he was in France with the French court master-builder Robert de Cotte, the architect Germain Boffrand, and with the philologist Bernard de Montfaucon. He also spent time in Leyden and London, where he studied the re-invented Feuermaschinen and possibly also met Isaac Newton. 
In 1722 he returned to Vienna. He sought and obtained, December 1722 a court architect position. After the death of his father 1723, Johann Lucas von Hildebrandt succeeded to the position of chief Court Architect. In 1725, Joseph Emanuel, succeeded in turn to this position, probably with the help of his powerful sponsor, Court Building director, count Gundaker von Althan, completing his father's unfinished projects. Though a successful architect in his own right, he was overshadowed by his more famous father.
In 1722 he returned to Vienna. He sought and obtained, December 1722 a court architect position. After the death of his father 1723, Johann Lucas von Hildebrandt succeeded to the position of chief Court Architect. In 1725, Joseph Emanuel, succeeded in turn to this position, probably with the help of his powerful sponsor, Court Building director, count Gundaker von Althan, completing his father's unfinished projects. Though a successful architect in his own right, he was overshadowed by his more famous father.
In 1729, Joseph Emanuel was appointed Imperial Court Chamber Advisor. In the course of his work, he exercised his technical abilities and dedicated himself increasingly to building steam engines for mine excavation. For this work he was made Baron in 1735.
In 1727, he had married Maria Anna von Dietrich, with whom he had 7 children. He had an important art collection and extensive library. His wife died in 1740. He died on June 29, 1742 in a house fire. He left an enormous fortune of 130,000 fl.
