You say you have 5 app and 5 meters is that correct? We have an app and have two meters, Night and day, But if you do only have one meter your bill isn't that high, Bearing in mind its your elec and heating all in the one, If you turn down the storage heaters by 1 in all the room's you will see a difference, We only use two of the storage heaters in out app and the amout of units its used is huge and the only thing that helps us is the fact its on the night meter, Best thing to do would be go down to the meter and read what it says at 11.59pm and when 12.01 comes and the rads start working go down and see what speed there doing, then go down in the morn a little after 8am and take a reading and you'll see the power there using. The communal power should be placed usually outside the building so the esb man can check it easier than your own one. Do ye have a management company and yearly fees?