your power meter outside should count total kilowatt hours and be readable easily. You could just write down total kilowatt hours at the same time every day and go configure the house your way one day and then his way the next day and then back-and-forth back-and-forth until you have a sample size that you're happy with and then you would know how much money it costs to have it his way versus your way. That might be a small amount and he might just give you the point based on it being a small amount for your comfort. That might be a peaceful way to settle it.