The Kunsthistorisches Museum was the place where Aryanised and looted works of art belonging to Jews and other persons considered ‘hostile to the state’ were stored. The central depot of confiscated art was established on the second floor of the Neue Burg under the administrative and scientific direction of the Kunsthistorisches Museum. The works of art had to be housed, inventoried, and exhibited. This new area of responsibility had necessitated adaptation measures in the museum, which were subsequently to be implemented.

In order to implement these building projects, a building department had been set up in the museum specifically for this purpose, and Helene Buchwieser had become its head. Her tasks included the elaboration and supervision of ongoing construction work and architectural issues of the restoration, and the interior design of the Secular and Ecclesiastical Treasury as well as the Neue Burg. This included various construction works, such as installations, glazing, adaptation of the sanitary facilities, renewal of the passenger elevators, but also the supervision of the remodelling, e.g. of the Palais Pallavichini, in which the music collection had been housed. She was also responsible for organising the installation of the Hitler busts by Edwin Grienauer and Wilhelm Fraß, and for planning the decoration in preparation for Adolf Hitler’s visit to the museum in March 1939. While working at the museum, she met her future husband, the Austrian art historian Lothar Kitschelt, an illegal National Socialist in the early days and a member of the SS. They married as early as 1939, but this forced Helene Buchwieser-Kitschelt to resign from her position at the KHM, in accordance with the regulations for married women in the federal service.

Her political orientation is difficult to judge. She was not a party member and never applied for membership in the NSDAP.

In 1940, she returned to her father’s construction company as deputy plant manager, where she remained until 1948. In this capacity, at the end of the war, she was responsible for securing and reconstructing St. Stephen’s Cathedral in Vienna, deputising for the cathedral’s master builder Karl Holey, together with her brother Bruno Buchwieser, Jr. The restoration of war-damaged buildings also played an important role in their activities in the following years. On 16 May 1940, she was the first woman to pass the master builder’s examination, and in 1945 she obtained the title of civil engineer for structural engineering.

A war widow since 1944, she married Josef Koller, a section councillor in the Federal Ministry for People’s Nutrition, in her second marriage in 1947.

Before she became a freelance architect 3 years after the end of the war, she visited the USA for 6 months on a scholarship from UNRRA (United Nations Relief and Rehabilitation Administration) to study housing and settlement construction, new building methods and new building materials.

Since her independence in 1948, she had been able to obtain a variety of work assignments. In the course of half a century, Koller-Buchwieser planned and built with a focus on residential and sacred buildings, as well as educational buildings, administrative buildings and private houses. Among other things, she built residential complexes for the municipality of Vienna, housing estates, social housing, student dormitories and housing for the elderly, orphanages, schools, libraries, and factories. Helene Koller-Buchwieser successfully participated in national and international competitions, where she won first prizes for a school centre, a student dormitory, a children’s home, and a funeral home.  Sacred buildings seem to have been a special concern of hers, which may have been due to her early work on churches and her family environment – her father was, among other things, a master builder for the Carmelite nuns. Thus, numerous churches and their outbuildings as well as extensions of convents were built by her.

In the later 1970s she was involved in reconstruction work in West Africa, for which she was even awarded the Pro Ecclesia et Pontifice Medal of Honour by Pope Paul VI. As further honours she received the title of professor in 1979 and in 1988 the pin of honour of Hinterbrühl, the municipality in which she had her residence.

Helene Koller-Buchwieser left behind an extensive body of work. She was an architect and master builder and possessed the necessary art historical expertise for her work. Her great affinity for church architecture, as well as her social commitment, gave rise to important projects. She defined her lifelong goal as finding creative solutions to contemporary needs and giving architecture a spiritual dimension.