All structures have a assumed use able life, which depends on the weathering action, chemical attack, embedded metals, alkali-aggregate reactivity, fire, due to overload, seismic forces, quality of materials used, techniques, workmanship etc. The large numbers of monuments, which are cherished heritage structures have stood well over a period of time due to best material and periodical maintenance. But some of these have shown signs of distress due to age, aggressive natural environment/industrial pollution etc. Further, distress gets aggravated due to overcrowding and misuse of buildings. Some Buildings have also failed due to faulty design, construction, bad quality materials, poor workmanship etc. The various causes of structural failure and the principles of rehabilitation of structures are discussed. In the structures, the cracks are generated due to different causes e.g. in some cases cracks are caused after the structure has been completed for a few years which results in shortening of life and strength of structure. The main criteria is how to repair a reinforced concrete elements of structures and for this the skills, knowledge, and experience required to repair damaged or deteriorated structures are decidedly different from those required to build new structures. The purpose of this paper is to justify the latest techniques, advanced materials and various requirements of repairing work to obstruct the deterioration which is necessary and economical than to reconstruct the building.