Haha, that’s probably true, but in that case you are too . You can look at current inside temperature and decide whether or not to heat or cool. If your heating system has enough power, it can react faster than weather ever changes. Anyway, in my case, the case for predictive heating is to spend electricity when it is cheaper, and avoid when it is more expensive. It changes by the hour. By looking forward, I could heat my home a little extra when the prediction is that more heating is necessary in the next few hours and the price will rise, and a little less when the price will drop and temperature forecast allows for it. However to do it properly, I must figure out at least the natural lag of my house. I already know the base consumption, which is about 1kW, which heats the house about 13 degrees over the outside temperature. The more granular one wants to get, the more aspects must be taken into account. If it was simple, we would have this figured out by someone else ages ago.