We changed to a water meter a few years ago at our old house. Monthly bill went down from £75 to £20Also I meant to say about water too ..
We had a water meter fitted 3 months ago. It won't be compulsory for us to be billed using the water meter for another 2 years but they are going to send a comparison bill every 3 months to show what we are being billed and what we would have been billed based on our water usage.
Even though we are quite good with water, I was a bit nervous about this, as we are a family of 5 so I assumed our water usage would be more than we are currently paying for. However, we had our 1st comparison bill in and we would actually have paid £30 less based on our usage.
I'm going to see what the next comparison bill is like and we might opt to switch to the water meter early. On our water companies (Thames) website they have quite a few water saving devices that they'll send out for free (4min shower timer, water efficient shower head, etc.) so I've ordered them and I'm going to try and make sure we're not wasting water.
Where we live now in South Wales, there was already a water meter fitted. We have converted one of our toilets so that it uses rainwater collected in water butts to flush the loo. There is 400 litres available directly, but if they need topping up we can transfer rain water from the water butt for the shed.
Water & Sewage Treatment charges are higher in Wales, but our bill is now just £15 a month.