This paper reflects on urban human settlement layers with an enquiry on a comprehensive understanding of urban spatial planning and development. It highlights varying scenarios of planned and unplanned human settlement layers in the urban context. Residential and commercial urban human settlement layers are examined. Economic engagement in urban human settlements is mainly none-agricultural undertakings and its population density is normally higher compared to that of rural. Human settlement rapid growth of unplanned urban human settlement layers is accelerated by high rate of urbanization with far reaching threat of leaving dwellers without access to basic physical and social infrastructure such as health centres, schools, churches, mosques, roads, streetlights, water supply, electricity, sewage and drainage systems. This study has employed case study method through Mbeya city in Tanzania to understand various urban settlement layers. Multiple data collection tools were employed such as literature review, interviews, observations, and photographic registration to gather information. The research found out that there is a problem of inappropriate use of resources and rigid urban planning regulations and legislations. Co-existence of planned and unplanned human settlements is the reality on the ground. Seventy percent of urban population dwells in the unplanned human settlements. The study argues that policy makers and professionals should give critical thinking on this reality in the formulation and implementation of national and global human settlement approaches and policies.
