The first-floor staircase is challenging to assemble. I recommend attaching the staircase backing first to ensure it is square and ready for the treads and risers.
Everything is straightforward until you reach the risers and treads. It seems simple - install the risers first, then the treads but they can only be assembled one way or it will affect the dollhouse construction. Make sure the treads are flush with the left side of the staircase and overhang on the right, as the left side needs to sit flush against the wall. This step is crucial. Dry fit the sides of your staircase to determine which side goes against the wall. Ignore any "right" or "left" labels; it's best to see for yourself to avoid mistakes. If you don't position the correct side flush, you won’t be able to fit the staircase properly.
Also, remember to use the shorter five treads at the top of the staircase. The risers on the upper half are too short to reach the ends, so I had to use clamps to squeeze the front together for a proper fit. The staircase appears straight. I did a dry fit beforehand, and it fit well, but I haven't tested it again after installing the treads and risers. I need to wallpaper the wall where the staircase will go before final installation.
