To be honest the fact they give you all apart from the floor and stairs is ridiculous!, they should restrict scaffolding, walls, doors, windows and roofs too. Then it doesn't give a false representation for the base building.
There is basically nothing which implies that it is the only thing which is locked. I mean come on the character can make everything else except floors and stairs? They have skill in making complex things like walls, doorways and roofs. But not floors?
Lock them all until you pass the start and then the player is pushed to explore the story. I was set on my survival style right away and was building myself a home after the first research station.
Like many others it seems...
Maybe just allow for tools, campfire, lean-to and chest until the rest is unlocked?