It’s got to be evidence based like any other charge. If they can show the previous year’s consumption, an appropriate break down betwren communal areas v tenants own rooms, and the new rates being charged, you should be able to see the link between historic costs and projected costs, and reach your own conclusion on the reasonableness of the new charge.
The issue I have is that costs are moving so fast right now we are barely able to play catch up.
