Functionalism has been closely associated with modern architecture; it is by no means an exclusively modern conception of architecture, apart from the fact that most fanciful architecture has practical functions to fulfill. This book however portrays functionalism in another perspective,which entails structural principles, aesthetic principles and constructional principles, viewed from master architects and critics, with a clearer insight and more detailed understanding to the basic requirement, kind of culture, philosophical knowledge and psychological insight while designing or planning a functional building. and its influence to the contemporary architects.