I find there are too many variables to identify the effect of individual changes, Tony. For example, a mild winter or a cool summer, the amount of sunshine which heats the house, how much lighting you need on dark days, how many times you use the washing machine or dishwasher etc.
Well yes there are variables, but the deeper you drill down on the data the more accurate it becomes. For instance I take meter readings every month.
The reason the thermostat is in the hall is that it can respond to the inrush of cold air when the door is opened.
That is the logic behind retail premises entrances.But controlling temperatures for a domestic residence is a different ball game, like I say I don't live in my hallway.
Simon, every time my provider informs me they are putting my direct debits up. I do the numbers, and inform them they are wrong, leave the direct debits as is. Because for the most part, this altering of direct debits is just a way them getting their customers to fund their cash flow. Why borrow millions of the bank at 8% interest or whatever, when you can borrow it off your customer base for bugger all.
Rule One in Life is: every thing they [they being every organisation, be it governmental or corporate] tell you, it's sole purpose is to part you from your money, Period.