Itâ€Ÿs been a decade since post-tension system began to be applied in earnest to buildingsrnworldwide. In the meantime, post-tension system has been used in various buildings as mainrnstructural system including tall buildings and it plays a role to overcome architectural limit ofrnregular reinforced concrete buildings particularly in the realization of long span with shallowerrndepth than other structural system. rnIn Ethiopia the benefits of post stressing and particularly of post-tensioning flat slab in buildingrnconstruction yet to be fully recognized. In this project an attempt is made to assess the level ofrnpractice, the problems and achievements on the design and construction of post-tensioned flatrnslab in Ethiopia through distributing Questionnaires to be filled by professionals currentlyrnworking on design and construction of buildings. rnThe study suggests that measures shall be taken for the top identified factors hindering the widernapplication of post-tensioned flat slab in our construction industry widely like; Universities hasrnnot been covered the topics deeply in under-graduate sections, Shortage of research literatures,rnseminars and related design examples, Lack of experienced consultant, contractor and otherrnengineering professionals and Lack of professionals and expertise. rnThe basic concepts, principles and advantages of post-tensioned flat slab design are discussedrnand also this project attempt to compares the cost effectiveness of post-tensioned flat slab systemrnwith respect to reinforced concrete flat slab system. Both the systems are analyzed using ETABSrnwhich is based on the design methodology. The results indicate that post-tensioned flat slabs arerncheaper than the reinforced flat slab systems. rnThe analysis of post-tensioned flat slab is basically a trial and error process in an effort to reachrnthe beast proportions. Manual computations of the analysis may take a time for engineers tornarrive in best design. The study of the spreadsheet analysis of post-tensioned flat slab usingrnExcel spreadsheet will be developing in this project. The design example is shown based onrnsimple procedures by using design excel spreadsheet including ETABS demonstrations.