What if one roommate uses way more electricity?
One flatmate is leaving the heating on while everyone's out. Or has an electric heater in their bedroom. Or runs a gaming PC 24/7. The bill is up 40%, the rest of you don't use as much, and equal split is starting to feel unfair.
Have a 10-minute conversation, not a sub-metering project. Either ask the high-usage flatmate to behave differently, or agree a flat winter top-up they pay. Both work. Sub-metering doesn't.
It feels like the fair answer. In practice:
We've never seen sub-metering improve a flatshare. It always signals that the conversation needed was the one nobody had.
Useful when the heavy usage isn't intentional - the heating is on because the heavy user forgot to turn it down when they popped out.
"Hey - quick one. The heating's been on quite a lot during the day; the bill is going to land high again. Can we all be a bit more on top of turning it down when we're out?"
Note the "we" framing. Most people respond well to this.
Useful when the heavy usage is intentional or unavoidable - the WFH flatmate genuinely needs the heating; the gaming PC user isn't going to stop.
"I think it's fair if the WFH-er pays a bit extra on the winter bills. Maybe £25 on top in December, January, and February? Sound reasonable?"
Concrete number, time-bounded. No measurement needed.
Have the conversation in October, not in February when the bill has already landed. Pre-empting it as winter starts feels like organising; raising it after a £400 bill feels like an attack.
Track utility bills in a flat group so the conversation, when it happens, is grounded in numbers everyone can see.
Free forever. No signup. Works in your browser in 30 seconds.