The populations of Windhoek and Rehoboth, located some 90 km south of the capital, are growing rapidly, leading to major construction to meet people's needs. Due to this rapid increase of the urban population and the resulting demand for housing and facilities in the limited space available, adequate groundwork, necessary for the safety and stability of the planned development, is often lacking. At three sites where construction for residential use was taking place, i. e. Rehoboth South, Rehoboth North and the suburb of Acacia in Windhoek, pertinent soil characteristics were investigated. Soil samples were tested for moisture content, grain size distribution and gradation as these factors, among others, determine the suitability of a building site and the foundation type to be adopted. Failure to ascertain carrying capacity and other essential aspects of the proposed site prior to construction start can have a significant impact on stability and - subsequently - on cost for later modifications. This study, carried out as a B. Sc. (Hons) project at the University of Namibia, provides basic information for construction work, emphasising the need of adequate building ground investigation both for reasons of safety and economy. It presents the findings from the investigation of three construction sites, which encompassed general site reconnaissance and geotechnical field and laboratory tests. Keywords: Soil characteristics, foundation type, moisture content, bearing capacity, gradation analysis, trace elements