Not particularly large. 3 bedroom, however on its own in the middle of nowhere. I have no idea why they needed to bring in a new line for the heaters, I assume because the single phase wasn't enough. Again it was done in 1993 by the looks of it. They fitted a 10kw shower, which may have had something to do with it. Heaters are 3 x 1kw, 3 x 2.4kw, 1 x 3kw and a 8/10Kw shower.
I was on an old tariff which gave more time for the heaters, so I had an off-peak cheap rate for the heaters. Of course, this meant day rates were crap. Technically not my property so changing the heating system is not an option currently. Another story.