The increasing amount of publications, the rapid development of vari ous formats of media, the annual accretion of library collection, the addition of readers, the new services rendered by libraries and the improvements made on library equipments have caused the problem of insufficient libraryspace. When such problem cannot be easily solved by more economicmethods, such as rearrangements of spaces, compact shelving ormicroforms, we have to solve the problem from library building itself eitherby constructing a new library, renovating, remodeling or building additionsto the library, etc. This article discussses improtant issues confronting remodeling, renovating and building additions to the original building. It investigates thestapes of implementations and points out the important related matters to beaware of. Two actual examples are given as sample cases for illustration.