When my kids were really young, like 1 and 2 (44 years ago!), I built an HO layout on a 4’ x 8’ sheet of plywood that folded against the wall. The frame was about 10 inches deep, and was mounted on the wall over a couch that could be used only when the train was folded up against the wall. The 10-in deep frame allowed for all the scenery we had to be permanently mounted on the layout, and only the trains needed to be removed to put the layout away.
For running the trains, the layout folded down and rested on a narrow set of shelves made out of 1” x 6” stock that doubled as the support legs for the side opposite the wall. The couch could not be used when the train was down, but hey, when you have limited space, some compromises have to be made
.Good luck!
Alex
