The problems of settlement in Port-Said area have been a great concern in recent years. Damages occur in buildings
due to urban development that requires constructing high rise buildings to accommodate the growing population. Raft
foundations have been used for new buildings in Port-Said. This is mainly due to the presence of soft clay layers, which
extends to depths that may reach 60m under the ground surface. This paper studies effect of constructing a new building
beside an existing one. Constructing of a retaining wall between the two buildings is studied as settlement reducer for
the existing one. Typical soil stratification and properties in Port-Said are considered in a numerical study to achieve
this task. A parametric study is also carried out to examine influence of constructing such retaining wall, and study the
effect of its variables on the existing building. Results revealed that constructing a retaining wall between the existing
building and the new one reduces the settlement under the existing building. The study also presents guidelines and
diagrams for proposed properties of such retaining walls that may be used in Port-Said.