Claassen began his professional training in 1900 at the royal Prussian district building inspection north. This was followed by studies in Hanover and Hamburg . At first he worked in various architecture firms in northern Germany. In 1911 he founded his own office in Meiningen . After his military service in the First World War, he worked in Soldau as the reconstruction architect of the war-torn East Prussia.
In 1920 Claassen came to Coburg, where in 1922/1923 he planned a villa in the style of reduced historicism for the Ducal Saxe-Coburg and Gotha administration . As one of the larger objects, the town hall of Zella-Mehlis was built in 1924/1925 according to his plans in the style of New Objectivity , based on monumental architectural forms of modernism. In 1925 Claaßen entered the service of Duke Carl Eduard von Sachsen-Coburg and Gotha and, as ducal building director, built two administrative buildings in Coburg, a memorial chapel for Helene zu Waldeck and Pyrmont , at the hunting lodge Hinterriß in Tyrol, also forest and workers' houses as well as economic buildings in Thuringia and in the 1930s renovations and extensions at Callenberg Castle . For many years he was chairman of the Coburg Art Association .
As a member of the building committee of the Adolf-Hitler-Haus-GmbH, Claaßen planned in 1933/1934 on behalf of the Coburg Lord Mayor Franz Schwede the conversion of the Coburg Society House into the representative party headquarters of the local NSDAP . In the following years he worked primarily as a consultant for the Coburg City Building Department and was involved in the planning of the new municipal buildings for the trade school, the count's block and the war memorial in the arcades . For the expansion of the Coburg town hall as part of the renovation of the Stadtsparkasse , Claaßen designed a new Coburg bay window on the corner of Rosengasse in 1938 , the "Führererker", which was to memorialize Hitler and Swede with reliefs and sayings of the Führer.
Claaßen joined the NSDAP in 1935 and held the office of commissioner for the Reich Chamber of Fine Arts in the Coburg district . From 1936 to 1940 he worked on drafts for a Gauforum and other monumental buildings in Stettin on behalf of Swede, who had been Gauleiter of the Pomeranian Gau since 1934 and President of the Prussian Province of Pomerania . His studies on "buildings in brick" in the imperial style mainly included drawings for administrative and party buildings. In 1940 Claaßen designed a district forum in Coburg for the local NSDAP on the then undeveloped Judenberg, with a parade avenue, a parade area for 10,000 people and a festival hall with an area of 3500 square meters.
The Spruchkammer Coburg-Stadt classified Claaßen as a follower in 1948 . In the same year he was retired from the ducal administration. In the following years Claaßen worked in Upper Franconia as an architect and advisor to the Evangelical Lutheran regional church in Bavaria. He designed various new church buildings and led the renovations and extensions of medieval churches.
New church buildings (selection)
- 1937: St. Johannis community center in Hof
- 1938–1939: Evangelical Christ Church in Hof
- 1946: Evangelical Church in Steinwiesen
- 1946–1951: Church of the Resurrection in Kleintettau
- 1950: St. Laurentius in Ebersdorf near Coburg
- 1953: Christ Church in Steinbach am Wald
- 1954: Church of the Resurrection in Stockheim
- 1954: Evangelical Church in Langenbach
- 1955: Friedenskirche in Wildenheid
- 1956: Gnadenkirche in Schauberg
- 1955–1956: Dr. Martin Luther Church in Creidlitz
- 1959: Kindergarten at the Augustinenstift in Coburg
- Christian Boseckert: "... so that Coburg becomes more beautiful"? The Nazi building policy in the Vestestadt (1933-1945) . (= Series of publications by the historical society Coburg eV , volume 26.) Coburg 2014, pp. 117–121.
- Helmut Wolter: Space - Time - Coburg. Volume 1: Coburg architects and builders 1820–1920. Dr. Peter Morsbach Verlag, Regensburg 2011, ISBN 978-3-937527-38-3 , p. 45 f.
- Helmut Wolter: Space - Time - Coburg. Volume 1: Coburg architects and master builders 1820–1920 , p. 45
|BRIEF DESCRIPTION||German architect|
|DATE OF BIRTH||July 30, 1886|
|PLACE OF BIRTH||north|
|DATE OF DEATH||February 10, 1960|
|Place of death||Coburg|