the design is based on 3 units design (Duplex 70+70m2 & 50+50 m2- Single Apartment 70 m2 - Studio 50m2) by organizing the 50 m2 units above each other and the 70m2 units above each other we can get the maximum number of units on each elevation and the maximum number of units/floor with minimum area for each unit still keeping the variety of units areas.