Universidad Politécnica has several campuses scattered around various areas of Catalonia and two of them are in Barcelona: Campus Diagonal Nord and Campus Diagonal Sud. Metro line 3 has two stops in Avenida Diagonal (Zona Universitaria and Palau Reial) and both of them are very close to both campuses.
Campus Diagonal Nord is located north of Avenida Diagonal in Jordi Girona street. This campus hosts the School of Telecommunications Engineering, the School of Informatics and the School of Civil Engineering.
If you are going to study in campus Diagonal Nord, Pedralbes and Les Corts are very close by. Pedralbes is located just north of campus and is one of the best residential neighbourhoods of the city. The campus is easily reachable on foot in 15 or 20 minutes from many areas of this neighbourhood. Les Corts district, where the legendary Camp Nou stadium is located, is an excellent area to find accommodation. The journey to the university only takes 14 minutes (metro line 3 from Les Corts to Palau Reial and then a few minutes on foot) .
Campus Diagonal Sud hosts the School of Architecture, the School of Building Construction, the School of Industrial Engineering and the School of Mathematics and Statistics .
If you are looking for accommodation well connected to the university, Sants neighbourhood is your best choice. The journey from Plaça de Sants to the University will not take more than 20 minutes in total; 7 minutes by metro (line 5 to Collblanc and then 9S line to Zona Universitaria) and the rest on foot. The neighborhood is not only well connected to the University, but also with many areas of Barcelona and the airport (trains from Sants station).