Considering this or this design with 3 levels apartments, do the doors/houses on the top floor count towards the village house count even if the villagers are not able to access them (via stairs for example)?
According to the Minecraft Wiki..
Villagers will recognize a house within sixteen blocks along both horizontal axes, and up to three blocks above or five blocks below the level of the ground the villager is standing on
Therefore aslong as the following conditions are true:
1) floor below the top floor is reachable by villagers
2) it is 3 blocks or less above the previous floor
3) have more inside blocks than outside blocks
They should count as houses even without stairs.