In an abandoned site, Burnitz was in charge of construction from 1816-1819 of Hohenzollern Castle in Hechingen which was never finished due to lack of funds. From 1820 and 1821 he travelled through Venice, Florence, Rome and Naples. By the end of 1821 he went to Frankfurt, where he gained citizenship in 1822. Burnitz belonged to a group of city architects including, and Friedrich Hull who shaped the classical Frankfurt cityscape of the 19th century. Despite his career as an architect, he undertook further travel within Germany, and also to the Netherlands and Belgium. Burnitz was appointed in 1824 to Inspector and Technical advisor by the Prince of Hohenzollern-Sigmaringen, Anton Aloys. In 1831, with the partnership of Frankfurt entrepreneur Johann Hermann Osterrieth, Burnitz founded "Kronthaler Actien Club", also called "Cur-Anstalt of Crone Thal near Cronberg joint-stock company". He then began work surveying and preparing a parcel of land. After obtaining a building permit Burnitz and Osterrieth built a spa and bath house with catering from 1832–33, to offer a luxury bath house to customers. However, by 1845 the company was resold due to a lack of profit. In 1832 he requested from the Senate of the Free City of Frankfurt to establish a steam mill. It would have become the first stationary steam engine of Frankfurt. The Senate approved its construction as a grain, board, and grinding mill, but Burnitz renounced his involvement due to this amendment. It was not until four years later that Senator Johann Adam Beil approved the first steam engine in Frankfurt to be constructed. From 1834 to 1837 he constructed the French Reformed Church in Friedrichsdorf. Then, from 1842–43, he constructed his most famous work, the Burnitz court hall, now part of the Historical Museum of Frankfurt. It is also the only one of his works in which he left his usual strict classic style in favor of a more neo-Romanesque historicism.
Burnitz married on May 2, 1823 Maria Sophia Saltzwedel. The marriage produced six children, including their eldest son and later architect Rudolf Heinrich Burnitz. Burnitz since 1833 also was guardian of his orphaned nephew, the lawyer and painter Peter Burnitz. Rudolf Burnitz died on January 28, 1849 in Frankfurt am Main. His grave is located in the Frankfurt's main cemetery in the Masonic Lodge of Frankfurt.
Architectural works
New Castle in Hechingen, unfinished
Supply Depot of Wiesenhüttenplatz
Orphanage
Metz Palais Lersches, Alt-Bonames 6
Israelite Hospital in Rechneigrabenstraße, 1829-31
Atelier-cultivation of his own home at Untermainkai
French Reformed Church in Friedrichsdorf
House of Alexander du Fay in the Neue Mainzer Straße and Manskopf cal residence on Untermainkai
Residence of the Leerse-Bernus family, known as the Burnitz Hall Court, now part of the Historical Museum of the City of Frankfurt am Main
Literature
Albert Dessoff: Biographisches Lexikon der Frankfurter Künstler im neunzehnten Jahrhundert. In: Heinrich Weizsäcker: Kunst und Künstler in Frankfurt am Main im neunzehnten Jahrhundert. Verlag von Joseph Baer, Frankfurt am Main 1909, S. 22-24
Wolfgang Klötzer : Frankfurter Biographie. Personengeschichtliches Lexikon. Erster Band. A–L. Waldemar Kramer, Frankfurt am Main 1994,.