The following examples provided by different retailers explain gas bills in more detail:
NOTE: Check that your bills reflect actual meter readings and not estimated consumption
If you have a central hot water system your owners corporation will generally not be billed for the gas used to heat the water.
For most centralised gas hot water systems:
- the gas needed to provide hot water is centrally metered at the hot water system
- each apartment is fitted with a water meter at the apartment’s hot water entry point which registers the volume of (hot) water flowing into the apartment
- a water meter on the centralised hot water system also records the volume of cold water entering at the inlet
- the gas distributor calculates the amount of gas used to heat the water, and charges each customer in the complex based on how much hot water they have used
- the water usage is multiplied by a ‘common factor’, which varies from quarter to quarter, depending on how much gas has been used to heat the total volume of water for the building
- The common factor applied to the billing quarter will be listed on the bill, usually below or beside the meter readings
Some points to note from the above:
- the owners corporation does not pay for the gas, individual residents do
- even if the cost per MJ of gas and a resident’s quarterly use of hot water remained constant, the application of a different common factor each quarter can result in different costs
Some older buildings don't meter individual apartment consumption and apportion gas costs according to unit entitlements. This is obviously even less satisfactory as it is not based on use.