Everything here is derived from Vanilla assets, so it is cohesive with the rest of the game.
Everything here is derived from the vanilla assets created by the developer. So I, nor anyone else, can claim copyright over this because it's all vanilla assets. (Recoloring & pixel placement can't be owned by anyone) So do whatever you want with this. It has the same rules as the vanilla assets from the game (100% owned by the developer).
Here is an image showing how these houses were created. Nothing is original artwork. Everything is 100% vanilla.