الخلاصة:
In this research (study of building R+3 of steel structure), we designed an 
urban building consisting of three floors and the ground floor,
In the design of the building we relied mainly on steel structures with the 
combination of the concrete roofs and the walls of bricks .
We presented the total dimensions of the building and selected the 
materials used, then calculated the loads and ensured the design.
After the feasibility study, we found that this type of building is 
economically costly, but it is more effective and consumes much less 
time than the concrete buildings, however the steel structures are widely 
used in military builds such as the military barracks of the National 
Gendarmerie in Al-Meniaa.