Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Includes bibliographical references (leaves 116-118).With the growing awareness of the rapid disappearance of the global fuel resources, energy conservation became an issue of general concern. Prompted by the results of studies done in the 1970's--which show a marked increase of energy consumption per square foot of office space over the years, as well as differences in consumption between buildings of different periods -- this thesis looks at the features that determine the considerable variation in energy consumption in office buildings from the beginning of the century to our days. An overview of the historic evolution of the highrise offices presents the events that influenced the change in energy performance.The elements that determine the energy use in a building, like its orientation, exterior envelope, interior design, and mechanical systems, are individually analyzed to present a detailed picture of their role. Their characteristics in the periods before and after the second world war are then compared, showing how they determined the energy performance of buildings of the respective periods.by Nora Anca Niculin.M.Arch.