The addition of ancient buildings and sites is an established phenomenon as old as 
architecture itself. It was a familiar phenomenon in ancient Egyptian architecture and 
Islamic architecture history. For example, the Temple of Hatshepsut was added to the 
Temple of Mentuhotep III site in Deir El-Bahari, and the Karnak Temple witnessed 
a series of additions to the original site built more than a thousand years ago. Egypt 
includes historical sites that are still alive and functioning, such as the Al-Azhar 
Mosque. In addition, it has heritage complexes from modern histories, such as Cairo 
University and the Egyptian Parliament. Therefore, it requires the knowledge of 
adding a new building to historical sites. 
The research discusses the issue of adding a new building to a historical site and 
presents its causes and problems. It also discusses the distinctive design approaches, 
strategies, and theories involved in adding a new building to a historical site. The 
research also documents and analyzes the layers of additions to the Cairo University 
campus, which witnessed a series of additions to its buildings and open spaces that 
spanned over a century and included additions of modern and postmodern styles to 
its original buildings, which were of the neoclassical style.