I was thinking: two different blocks, one is a stair block, one is a chair block. One costs less, one costs more and is un-craftable. This would fit with your problem because if you built your builds with stairs, you wouldn't suffocate.
~ @Zoe89
Would the "un-craftable" block still be a stair block, but just called "Chair"? Or would it be a different block? Would the chair block be the one more expensive? If so, how expensive? Would there be a shop exclusively for chairs? Or would you annex selling these chairs with /warp market? You would have to have a spruce, oak, old oak, birch, jungle, stone brick, and etc. chairs so it gives players full access to different colors and textures of what chairs could be. Would chairs be able to be placed upside down (I hope not)? Would chairs work if they were upside down?
"This would fit with your problem because if you built your builds with stairs, you wouldn't suffocate."
But so does my suggestion. The idea is just that if there is a block on top of the stair(chair) block, the stair doesn't allow you to sit in it. Anyway, thanks for the suggestion to the suggestion.
