http://news.bbc.co.uk/1/hi/business/7227793.stm
So now they are going to bill by house size - how do they know how many bedrooms I've got?
And who took part in this survey? Not me!
Actually they always have charged by property size (in the good old days they used the rateable value which was based on the size of the property and its rentable value) Counting bedrooms has been common practice in many places. Then they switched to judging your water usage by house value, reasoning that the higher the value the larger the house and thus the more people would be in it using water but regional differences have blown that idea out so they resorted to using the Council Tax bands (which are of course based on the size and estimated sale value of your property ... which is pretty mush that same thing but "they" pretend it is different). The current thinking is that the more bedrooms you have the more people MUST live there and therefore water usage will be higher. This does not take into account a house with 15 students who never wash themselves or their clothing until they go home to Mum OR a little old lady living alone in the only asset her deceased husband left her.
The best answer is to insist on having a water meter and pay for what you actually use. I did this, against the advice of the local water authority (you have a legal right to make them provide a meter) and reduced my water bill by 50% from what they proposed to charge for my 4 bedroomed house.
Sewage is charged as a % of the measured water coming in. Always has been and will continue to so be even with a meter but again I found that by having a measured amount in I could argue for a better output measure. (Why no meters measuring outflow? Well they can't measure the solids!)