Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Includes bibliographical references. / Studies about residential passive solar heating have been conducted in many countries, mostly dealing with new or existing single family houses and nearly unlimited access to the sun. Only a few studies are related to residential projects that use passive solar in an urban context and must cope with limited solar access, fixed city layouts, and constrictive building laws (1,2,3,4). Multifamily housing in German cities accounts for a major portion of the existing building stock. A range of German energy standards try to enforce the improvement of old and poorly insulated structures by these efforts only support conservation. As yet there is no initiative to seek optimal use of available solar energies. The heat loss in multifamily housing is already reduced to a significant degree: only a small number of weather walls and windows create actual heat losses, and internal gains act as beneficial heat sources which lower the demand for space heat. With increased use of solar energy, the usual 8.5 month heating period could be substantially shortened. Calculations included in this work show the potential for reducing the annual heating season to less than three months. Case studies of two tenement building types generic to the city of Berlin describe the existing situation in Germany and explore possible approaches for improving the use of passive solar energy by combining new and innovative materials with the existing building stock. All the factors related to climatic responsible design under local conditions are explained in a step-by-step procedure suitable for use by any architectural office concerned with using passive solar energy in an urban context. / by Alexander W. Lohr. / M.Arch.