South East Water assessed charge

GavB79

Hi,

I recently moved into a 3bed terraced property that is not metered. The rates are c.£200 water and c.£250 sewerage, p.a.
Being just me living here, I asked for a water meter and the surveyor said I was on a 'rail' supply so the meter would have to be internal, and I would have to bear the cost of the plumbing to make available 300mm of pipe between the supply and the first point of use.
As I am renovating the house I will get round to this eventually, and in the meantime the guy said I could have a single occupancy assessed charge.

I've no idea how long this adjustment will take to come through (survey was just last week), so is anybody able to suggest what the likely difference will be to my bill?

Thank you