David Hare-Scott wrote:

What is higher the cost or the amount used?

Well, the cost of ours is going up all the time,but that seems to be
charges.

Assuming its the amount check for
dripping taps, running toilet cisterns and leaking pipes all the way around
the system from the meter to every outlet. You (or a more mobile friend) may
have to get under the house up in the roof etc to trace the pipes.

First off, turn off all taps in the house and go see if the water meter
is ticking over. slow leak? read if before and after you leave for wor
forthe day.