any good space for this purpose?

any empty classroom after hours

but can you use the projector in the classroom? aren't they locked

If you book a room usually they'll tell you how to unlock it. Depends what building and what you're booking for, though.

You can borrow projectors from the libraries. They used to allow you to take them out of the library, but I'm not sure if they still do.

Their locked.

You can plug into many of the computers even after hours, I've done it in KTH and a couple of other places. As long as you're not climbing onto a desk, etc. to plug it in directly to the projector security will leave you alone. (They do have cameras in a lot of the classrooms and will come to tell you to stop if you do that).

Use the tutorial rooms in bsb basement.

U can use both the projector and the rooms speakers. Most of the time the black box isn't locked, even if it is, it's not hard to crack. The code is usually the room number.

Used to use all the time to do assignments with my group over the weekend.