Loose I pay £140 a month for a 3 bedroom semi where the family are out at school and work all day.
You need to make sure your meter is read every month cos the gas companies are buggers and they will tell you your monthly DD's are low, not read your meter for a year, then when they do read your meter, you'll owe them hundreds of quid and therefore can't afford to move to a cheaper supplier.
Also, stupid question, but check what type of boiler you have. It turned out that my hot water advance has been on 24/7 for 8 years! The previous occupiers must have left it to constant and never having had a conventional boiler and only having had a combi boiler I didn't realise just how much it would cost, as we moved in to it being switched on the whole time I thought that was normal! So I couldn't understand how we were using so much gas. Last winter we had a phase where we nearly froze as I didn't dare put the heater on. It was only after posting on MSE I discovered it was the water heater!
So this month I used £27 of gas and the same quarter last year £61.89 - and that was a summer bill! I used a bit more electric this month than I did the same month last year but I've been using the tumble drier a lot more.
I also bought a £20 electric fan heater which costs around 25p an hour to run just to heat up the front room and take the chill off.
Last month I used £60 in electric as we leave everything on standby and I've been using the tumble drier more frequently and the electric heater so we could cut down on that and really I need to keep up to date with my clothes washing and not let stuff build up.