Hanna Löv attended the Städtische Höhere Mädchenschule, where she graduated with her Abitur in 1919. Subsequently, she studied architecture at the Technical University of Munich until 1923. She then worked in the construction department of the Oberpostdirektion München, where she collaborated with Robert Vorhoelzer. On September 30, 1928, she became the first woman in Munich to pass the examination for the state higher civil service - ranking top of her class. This made her the first female Regierungsbaumeisterin (government master builder) in Bavaria, Germany. After 1927, she continued to work in the civil service and lived in Munich.
In 1928, together with Erna Meyer and Walther Schmidt as representatives of the Postal School of Building (Postbauschule), she developed the Munich Kitchen or "Essküche" for the experimental settlement of the Bavarian Postal and Telegraph Association. This was an attempt to find a middle ground between the new, highly rationalized "working kitchen" and the perceived old-fashioned and unhygienic living kitchen.
In 1940, Löv moved to the construction department of the Reichsbahnbauamt (Reich Railway Construction Office). Here, she was primarily involved in the construction and renovation of purpose-built structures for the Reichsbahn (German National Railway). During World War II, she was also involved in the camouflage of Reichsbahn buildings and facilities.
After 1945, Löv initially worked as a freelance architect. Later, from 1951 to 1957, she was employed at the University Building Office, which was led by Robert Vorhoelzer at that time.