Vernacular African settlements and buildings are widely appreciated for their human scale, aesthetic clarity and harmony with nature. But this appreciation appears to be limited to their iconic and picturesque qualities, and there seems to be little understanding of the value of these architectural traditions as products of historical, ecological, cultural and economic circumstances. This study compares a traditional Tonga compound at Siamundela, southern Zambia with a Banoka village near Khwai in the Okavango Delta, Botswana. Whereas Siamundela is totally remote, the Banoka are occasionally exposed to passing safari traffic. These case studies demonstrate how the built environments of different cultures reflect changes in social structures in response to the varying degrees of exposure to external influences. The two case studies are described in terms of context (historical perspectives, socio-economic and cultural conditions, geography) and dwelling and settlement patterns. The emphasis is on a comparison of spatial organisation and fabric.