Cool! I'm doing something similar, but more from the data-analysis side of things for my condo's efficiency. I've been trying to keep a blog of my progress, if anyone is interested, though please forgive the poor grammar / stream-of-consciousness in the posts... I've been writing quickly to get caught up. https://dan-nadler.github.io/
Looks interesting, bookmarked it for later reading :) I noticed that you have sensor in all parts of the house from the images. I wonder how did you solve the wiring issue? I mean I'm looking for a cheap way to connect all sensors, but avoid putting wires everywhere.
Initially, I had planned to wire through the basement, but getting through the floor turned out to be a littler more difficult than I had hoped.
At the moment, the wires are run under carpet and behind furniture. I just ordered another Pi (and am looking at cheaper boards) to set up another 'base station' to reduce the amount of wires I need to get full coverage.