It is an underground space which allows a city to accommodate double the number it could with out expanding above the ground level.
Its an underground transit hub which was design on the most crowded CBD area in Addis Ababa which is called Megenagna, in order to minimize the disorganized settlement due to the rapid urbanization and also to balance the consumption and production level.
1 selection of a specific site
2 site analysis
3 designing programm
- extruding down wards according to the main shape of the site
-cascading of the floor area
-solid void relation ship on existing shear walls
-chaotic organization of slab
-opening a major open to down