Jugendstil era renderings of interior and exterior spaces by Austrian architect and designer Marcel Kammerer (1878-1959) with help from his friends on some of them.

Design for Bakolowits Söhne glassware shop, Vienna. 1911.
Design for Bakolowits Söhne glassware shop, Vienna. 1911. Pencil, black ink, color pencil, color washes and gouache on paper. Emil Hoppe, Marcel Kammerer, and Otto Schönthal , makers. © Estates of the artists. Fair use license. via https://www.drawingmatter.org/index/hoppe-kammerer-schonthal-design-glassware-shop-vienna-1911-dm-1953/#&gid=1&pid=1
"Grand hôtel Wiesler à Graz (Autriche), salle des fêtes." (design for a hotel restaurant). ca. 1912.
“Grand hôtel Wiesler à Graz (Autriche), salle des fêtes.” (design for a hotel restaurant). ca. 1912. Pencil, pen and ink, watercolor and gouache on tracing paper. Inscribed “AUS DEM FESTSAALE DES GRAND HOTEL WIESLER IN GRAZ” in black pencil. Marcel Kammerer, maker. Collection of the Musée d’Orsay, Paris. © DR – RMN-Grand Palais (Musée d’Orsay) / Hervé Lewandowski. Fair use license. via https://www.musee-orsay.fr/fr/collections/catalogue-des-oeuvres/notice.html?no_cache=1&nnumid=93165&cHash=7610ae0c30
"Design for apartment building, Martinstrasse 17, Vienna." 1910.
“Design for apartment building, Martinstrasse 17, Vienna.” 1910. Pencil, black wash and gouache on paper.Emil Hoppe, Marcel Kammerer, and Otto Schönthal , makers. © Estates of the artists. Fair use license. via https://www.drawingmatter.org/sets/portfolios/architects-wagnerschule/
L. Köllner Shop Front, Kärntnerstrasse, Vienna." 1911.
“L. Köllner Shop Front, Kärntnerstrasse, Vienna.” 1911. Arch. Emil Hoppe, Marcel Kammerer, and Otto Schönthal, makers. © Estates of the artists. Fair use license. via https://www.tumblr.com/search/marcel%20kammerer
"Trabrennbahn (race track) Krieau, Vienna." 1919. E
“Trabrennbahn (race track) Krieau, Vienna.” 1919. Emil Hoppe, Marcel Kammerer & Otto Schönthal, makers. Estates of the artists. Fair use license. via https://www.tumblr.com/search/marcel%20kammerer

Castles in the air, architectural drawings out of the Viennese Secession to dream your way into. Not sure they were all even built and not sure that matters. Otto Schönthal, architect (1878-1961).

Design for a villa. No date.
Design for a villa. No date. © Estate of the artist. Fair use license. via https://all-drawings.livejournal.com/449497.html
Architectural rendering. 1902.
Architectural rendering. 1902. © Estate of the artist. Fair use license. via https://all-drawings.livejournal.com/449497.html
Design for a domed synagogue, Trieste. ca. 1903.
Design for a domed synagogue, Trieste. ca. 1903. Pencil and colored washes on tracing paper. Collaboration by Schönthal with Emil Hoppe. © Estates of the artists. Image © drawingmatter.org. Fair use license. via https://www.drawingmatter.org/index/emil-hoppe-and-otto-schonthal-design-domed-synagogue-trieste-dm1923/