The room in which I created the model has a usable surface area of approximately 30 m2, but has several constraints to take into consideration, shown in the figure.
The designated area for the model is on the right side, in the area between the end of the door and the French window that opens into the shaft. This wall is 5 meters long. The most critical constraint is the space on the back wall between the right corner and the window, which is 95 cm.
Since the room is 4.3 meters wide, to allow for easy passage, only 2.5 meters can be occupied. The free space left, in addition to allowing for other uses, will allow the model to be moved on wheels to access the rear parts on all sides.
Unfortunately, as you can see from the photos, it won't be possible to remove the model once completed unless you create many small modules.
The area on the right between the two windows is intended for a work table and other furniture. The L-shaped cabinet at the back will then be moved to the opposite corner.
Finally, the lighting needs to be changed and optimized to enhance the model itself.
In conclusion, the net space available for the construction of the model is L-shaped, with a long side of approximately 5 meters and short sides of 2.5 and 0.95 meters, with the possibility of closing the L diagonally to provide a net surface area of approximately 8.4 square meters. The chosen location has many advantages and one disadvantage. One clear advantage is the considerable available surface area; furthermore, by moving the model (assumed to be on wheels) diagonally towards the center of the room and towards the entrance, access on all four sides would have been possible with at least 70 cm. The main disadvantage is the presence of the French window on the short side of the L. Unfortunately, this left only 95 cm for the helical ramp leading to the main station, and consequently, the double track of the main line would have required radius 1 for the internal track (fortunately descending).