We found our plot in the centre of the city of Basel. It? s an extrem geometry, 30m long and 5m wide, with facade to two streets of different category, one comercial, the other one residential. It used to be a sloping comercialpassage. We could find this same situation in every downtown of every city in the worldNext step is try to understand what does living in the city mean?. Why do we choose the city? People wants the facilities and the leisure it offers us. The city is our HOUSE. The time we used to spend in our livingroom, is nowadays shared with the cinema, the theater or a museum of art. We share our lunch with somefriend in the restaurant or we just go to the park to enjoy our free time. Which is the role of the house in the city? What do we expect when we arrive at home? When we think about our home, wei magine that traditional geometry of house in which we feel comfortable. And this is our envelope, our shelter in the city. It? s all we need. Coming back to our ancestors, we just seek a cave in thecity, in which we can customize the free space.