As you need, I kept all the existent tables and stools. To fit the design I suggest you to change the stool's pillows into some white ones, you can see it on the renders.
I have worked on a serious but casual style. The design is clean and the space flexible.
In the red area I have created some lobby area with your existing tables and stools and also a space with some sofas. Also I have created some lockers in the wall for the students to store their own things.
To give you a marine style that links with the existing furniture, I decided to close the meeting rooms with glass and wood sliding doors. They can be opened and the space gets totally free of walls.
In the class area (capacity of 168) there are some simple but elegant white chairs to not charge a lot the ambient. Also in the top wall there are some sofa areas with carpets to work in a relaxed way or just chat with other students and all the wall is painted with blackboard paint so the students can use it as a creativity wall to do brainstorming or just get motivated with some positive quotes.
Finally, the two phone rooms are located next to the blue area. I decided to keep the red area as clean of walls as possible to make the space really flexible.
