Ok, against I start this because, is a official task and is time to start developing.
@Juli51
in charge of this task is @Enrique as departament leader. But you can have help from the rest of artists.
if you want starting quickly with a buildings and avoid read lots of very specific architecture, I can help providing material.
so start for Africans around Ptolemy Egypt.
We can start with Kushites. With houses.
A lot... The problem is reference-ability. Most of Saharan and Sub-Saharan African history from Antiquity, especially in the BC period, is steeped in obscurity. Literate and urbanized civilizations are also rare in this period. The major literate and urbanized civilizations of the period are the Kushites, the Habesha (D'mt, proto-Aksumites and the Aksumites) and the Garamantes. But I'm sure you know about them by now Kushites are more or less done (just details now). The Habesha/Early Aksumite