In case you cannot wait for the design project to start, you can already participate in Skanska's Sustainable Cities Challenge. This is a design competition for all students at Swedish universities (not sure if exchange students can participate as well).
This challenge is mostly focused on sustainable buildings and urban planning and it could be a fun way for you to gain some experience in the field of Sustainable Design.
For more info check their website: http://www.skanskasustainablecities.se/competitions/skanska-sustainable-cities/pages/english--2
Lakin and Heleen