How to Handle a Roommate Who Leaves Windows Open in Winter (2026)

It’s 34 degrees outside and your roommate has their bedroom window cracked, the hallway window open, and the kitchen window flung wide because “the food smell was bothering them.” The heat is running nonstop. The gas bill is going to look like a car payment.

Here’s how to handle a roommate who leaves windows open in winter: address it as a bill problem, not a habit problem. The behavior isn’t the fight — the bill is. Once the money is on the table, the behavior usually changes on its own.

Why “just ask them to close it” doesn’t work

You’ve asked. They agree. They forget. The window is open again by Wednesday. This is normal. People don’t feel a temperature drop in real time the way they feel a cash hit at the end of the month.

The move is to shift the consequence from “I’m annoyed” to “you owe more of the bill.” That’s not passive-aggressive — that’s exactly how utilities are supposed to work. The person who uses more pays more.

What’s the fair way to split the heating bill when one roommate wastes it?

You’ve got a few options depending on how bad it is.

Even split, one warning. If it’s a one-off — window open one weekend, everyone forgot to close it — split the bill evenly and text a heads-up. “Hey, gas bill was $180 this month, up from $95. Let’s keep the windows closed when the heat is on.”

Weighted split. If it’s chronic, weight the bill toward whoever’s running the windows open. A rough formula: whoever’s causing the waste pays their normal share plus half of the delta from a typical month. So if the bill jumps from $100 to $200 and one person is the reason, they pay their $50 share plus $50 of the extra $100, and everyone else splits the other $50.

Cap-and-charge. Set a bill cap based on a normal month. Everyone splits up to the cap evenly. Anything over the cap goes to whoever’s causing the overage. This is the fairest long-term system if you have documented history of who’s leaving windows open.

For a broader framework on splitting bills when usage isn’t equal, see how to split the electric bill fairly with roommates and how to stop a roommate from wasting AC.

The script that actually works

Skip the passive-aggressive note. Send this in the group chat when the next bill comes in:

“Gas bill is $[amount] this month, which is $[X] more than last month. Windows have been open a lot — can we agree to keep them shut when the heat is running? If it stays high next month I think we should look at splitting the extra by usage instead of evenly.”

That’s it. You’ve named the problem, tied it to money, given them one month to change, and previewed the consequence. Most roommates will adjust. The ones who don’t just told you exactly who’s paying the surcharge next month.

When it’s a real conflict, not a temperature preference

If your roommate is opening windows because the apartment genuinely feels hot to them and freezing to you, that’s a thermostat compromise, not a bill split. See how to compromise on the thermostat with roommates. Solve the temperature disagreement first, then talk bills.

How homies handles it

homies tracks utility bills month over month, so you can see the exact spike instead of guessing. When a bill jumps, the app can flag it and suggest a weighted split if one roommate has been running the AC or heat harder than the rest. The math is done, the receipts are logged, and the conversation stays about the numbers instead of who’s being unreasonable.

rooming, minus the drama. Join the waitlist at joinhomies.app.