She completed it after only two semesters. The design she worked out in it was the basis for her dissertation, submitted a little later, entitled: ‘Untersuchungen über städtebauliche Probleme insonderheit der Assanierungen’ (‘Studies of urban development problems, especially redevelopment’). As part of her dissertation, she made 87 hand-drawn sketches, with the core of her work being redevelopment plans of individual neighbourhoods. London slums were also covered in her dissertation, as she travelled to England in the summer of 1936 and worked for the then London-based Viennese architect Michael Rosenauer. During this time, she took the opportunity to attend lectures and tutorials at the Architectural Association, School of Planning and Research for National Development in London. She was interested in lectures on planning economics, building codes, urban surveying, planning statistics and urban planning. Lionore Perin graduated on 16 December 1936 and was the third woman to earn a Doctor of Engineering Science degree from the Technische Hochschule.

She worked for Michael Rosenauer in London for a total of one year before finally returning home to Vienna in the summer of 1937.

Back home in Vienna, she took part in a competition for an orphanage in Athens and in a competition for Grinzinger Strasse, which, however, did not achieve any external success. At the beginning of November 1937, she found employment with the construction firm Hofman & Maculan, where she worked as a construction manager until the end of March 1946.

On 26 July 1946, she obtained the license of an architect, which she changed to one for building construction in the same year. During a joint project in Lower Austria, she met the civil engineer Friedrich Regnier, who was then working for the Verbundgesellschaft. They married in June 1951 and a year later had their son, Thomas.

As an independent architect, Lionore Regnier, as she called herself after her marriage, was instrumental in the reconstruction of Vienna and planned several post-war housing developments. She carried out a number of building projects together with her husband and took part in several competitions. She died after a serious illness on 19 October 1970, at the age of only 58.

A research report on Rudolf Maculan is available from a research group that was commissioned by the City of Vienna from 2011 to 2013 to investigate the historical significance of those personalities after whom Viennese streets were named.