How to install the stairs? Is there a door?

The methods of installing the door are: Z 1. The stair door needs to be primed in the door cover first, otherwise the door cannot be installed normally. If you install the door in this way, it is best to use the joinery board as the primer and then install the door.

If you like concealment, you can make a wallpaper sliding door like a wall, just like a secret room.

You can add a partition, and then you can add a door on the basis of the partition, so you can add a door to the open living room.