So the number of houses need to be ~3 times more than villagers. If I have 10 villagers, and want one more, I will have to have 32 houses (Is that right? 32 * 0.35 = 11.2) But for a house be considered "valid", does a villager need to see it? I'm not sure if I read it correctly on the wiki.
Most of my villagers hang around the far north of the village, and there are plenty "abandoned" houses to the south. What should I do? Take a villager on a minecart and go around the village will make all my houses valid? Will that work?