Absolutely get a copy of the bill . Are you sure the primary expense is electricity ? If so , your cooking is not a factor and your hot water use probably isn ' t either . Unless the radiators are individual plugin units , those are running on hot water from the possibly gas boiler as well . If the radiators ARE electric however , they could easily be the culprits . Other housemates may be leaving them on all day now that the weather is cooler . When you get home , put your hand on each one to see if any are turned on when nobody else is home . Look for timer settings that automatically turn down the heat during the day and late at night . If you have a gas boiler , these settings would be on the boiler itself . Google the make and model number to find a PDF of the user manual . On the bill itself , is there a higher tariff for day use vs . night ? What are those tariffs ? You can shop around to see what various energy suppliers are currently offering , and then tell your landlady if she is overpaying per unit of energy . Is this an estimated bill or based on actual meter readings ? Do the readings match what you see on the meters themselves ? Do the meter serial numbers match your meters ? Is it for one month of use or multiple ? Is there a late fee or other nonuserelated charge included in the total ? Perhaps , if you show an interest in getting to the bottom of the issue and dramatically reducing future bills , your landlady will seek less from you and more from others . At most you two should pay no more then 27 of the portion she wants to pass along to tenants . Don ' t let anyone say the child isn ' t using a full seventh of that energy either especially if they take baths instead of showers and watch TV .