This article analyzes the design process of Yona Friedman. Friedman was a conceptual creator of mega - structures that were multiplied in several layers of cities in which users were responsible for choosing designs while being informed of the consequences. They used a computer containing the design options and described their way of life, which was translated into the use of environments. According to the spaces chosen from this list, the user could reconfigure the space. Although, considering that the city was an environment, the space could be selected while watching a computer simulation. Users’ choices depended on absolutely parameterized rules.