Heidrun Fleege was born in 1947. She worked in the project planning department of the Potsdam housing construction combine (WBK) and was entrusted with type projects. At the same time, she built up her own business and also did planning for private clients. In addition to single-family houses, she was also involved in monument preservation work on the Brandenburg Cathedral and other restoration projects.

In the 1980s, she completed an additional course of study in the field of monument conservation and the preservation of buildings at the Technical University of Dresden.

In order to counteract the continuing decline of the old town in Brandenburg an der Havel, she was also active in the working group for the preservation of monuments within the Kulturbund, which she founded with colleagues in 1985. She actively campaigned against further demolitions and carried out conservation work.

After reunification, Heidrun Fleege remained active as an architect, especially in Brandenburg, and among other things co-founded the regional association of the BdA Brandenburg. Even today, she continues to campaign for historic buildings.