Discovered why the electricity bill was so high

Suddenly since last month the utility bill jumped from 150 to 400. I had my suspicions and voiced them out that maybe the washing machine is being used way too many times compared to before. 1st flatmate who is local said no it is just government issue as they raise water and electricity bill for everyone. After that no one said anything because that is true. But I still had my doubts.

on a very random day I wake up in the middle of the night to drink water and see 2nd flatmate who lives in lower rooms near shared space is sleeping with her room open. Why? Because she is sleeping using the shared area stand-fan by keeping it near her room. The wire is almost going to tear that's how close she pulled the fan to her room.

Now I connected a few dots. Every night she got home at 2/3/4am and kept using the fan by staying in the shared space claiming she's going to study so she will be using the fan. It's a very noise fan. But it was agreed we can all use the shared space whenever for studying eating and doing whatever except sleeping/napping because working around a sleeping person is difficult.

She is not a student who studied so much in the past. This just started recently. Every night I would hear the fan and think she's studying. But actually she was just using the fan to sleep all night while we kept paying the bill. Normally we paid 30 each. Since she started this we are paying 100 each,(4 flatmates).

The first time she turned it off by pretending she forgot to turn it off before she went to sleep and she suddenly fell asleep while trying to nap for 30mins.

But today I saw after she came home she showered and started preparing to sleep by pulling the fan closer to her room. She doesn't care if she sleeps opening her room. It was more clear because the moment I opened my room door she immediately ran out of her room, turned of the fan, pushed it away and went inside her room and turned off the lights.

I discussed this with my other flatmate already and I have let her know what I saw today just now. We are most probably going to call her out on it since I have proof now. At best what we can do is take away the fan at night if she doesn't stop using it.

If anyone wonders, she is the richest among us all, she goes out using taxis for even 5min walk because she feels lazy, she eats out at very expensive restaurant everyday. She is not suffering financially in any way. She is just a very selfish and inconsiderate person who tries to burden others.

Common details.

The apartment is rented from an agency. Each room has an attached meter. Each person pays their own individual room rent+ shared electricity room utility. It is a duplex kind of flat. Two rooms up, two rooms down. Rooms down cost less compared to upper rooms. Lower rooms are just beside the shared space sharing walls.