We're still waiting for this almost 3 years later. This seems like such a simple thing to add since it's already available in other components of planbook (adding attachments to lessons, etc.)

Yes, please! I make PowerPoints for my Reading class so that each day of a unit is a slide that I project for the students to see. I think it would be much easier if I could attach it to the unit rather than to each lesson!

This has been "planned" for more than 2 years now. They've already made it super easy to add attachments to lessons. How much more difficult is it to apply attachments to units? Would also like to be able to connect lessons from multiple subjects to a unit.

I agree. Often documents pertain to the unit as a whole, but not to a specific plan. However, these documents need to be linked to each lesson also so that you can access it from any of the linked lessons.

I usually have exact materials that are connected to the unit and it would be great to add them right as i create a unit, so later when I select the unit for the lesson, the attached files would also appear.

I have documents that I need to upload to my units but not to individual lessons. Sadly, I cannot do that at the present time within Planbook.