A "repentina" is a project we undertake each semester. It's a "surprise" project, because the students don't know what it's gonna be about. Only until the day the repentina starts, at 8 a.m., the professors let us know about the subject. This project was done in about 8 hours of non-stop work. This project's objective is to design a high density neighborhood which could house over 1700 people. The project had to be designed with sustainble basis such as: local materials, low cost solutions, natural ventilation and illumination, adequate spaces for social gathering, graywater reuse and rainwater harvesting, etc.