It can very well be covered by panels that document the experiences that happen in that room over a period of the school year. The panels would include photographs of children experiencing project or idea or concept or . . . Where I work, all the posters etc., just came down in June. An agreement was reached. Our walls would remain blank until they could be filled with documentation.
Documentation represents enriching experiences.
Blank walls represent experiences yet to happen. The story of the walls should be the story of the year in that room. I really want to caution you about using photoboards as documentation. Photoboards are a start, but they are an incomplete communication, they take a translator - like looking at your own personal photo album with another who wasn't there. The words on the documentation should convey the communication of what happened, how it happened, why it happened, who it happened with . . .