Gas and Elect costs

General Discussion

I have a property which has been split into three units. A large flat upstairs and 2 x smaller flats downstairs. The gas and elec are supplied to all from the same supply as the upstairs flat was historically above a shop, so never separate gas and elec. I have been putting the gas and elect charges in with the rent - approximating a fair amount to each tenant accordingly. This last year the bills came to nearly 5k because they abused it. It's going tobe a lot more with the increases . I want them to pay separately for what they consume from now on. Getting a separate supply to each is not possible. Wondered if any other LL.s have got a similar property and how they approach this conundrum.