skeeterjo and UndraftedFreeAgent thank you very much for the information. As I have mentioned in a previous post we are not planning to live together in the first one or maybe two years of our studies. Instead we hope that we will do it well in the quals and the courses that are necessary in the first four semesters (I am doing a Ph.D. in Physics and my girl in Engineering) and after finishing all the necessary exams and courses, including quals, I hope that it will be possible to live in the mid-way. And I mean that this will be the case when the only think that we will have to do will be our research leading to our thesis. I do not think that this is impossible if you make a good work in your department and if you manage your time perfectly. In the meanwhile it is always easy I think (or hope) to move in each other's place in the weekends.