One year my art club was approached by a local business (travel agency) to do a mural on their wall that was travel related. (You might want to approach local business that have a walk in clientelle and ask if they want a makeover....good PR for your department).
Another year one of my gifted students (I taught G & T) redesigned the teacher's lounge with input from the teachers (like a client), using the furniture they already had, plus she added accessories. She redesigned the entire space keeping comfort and function in mind. That is always a great project and makes the other teachers aware of what art kids can do.