My roommate keeps opening the windows.

[Heisenberg]

Do you not know how cold it is outside?

[LightAlysCity]

Deck him in the nose.

[Heisenberg]

Maybe that'd stop him from snoring too.

[natsumehack]

Sorry but the winter outside is so nice.

[idlehands]

Lock him outside

[Cpt Toellner]

Just start pretending he doesn't exist and get all spooked and terrified every time he tries saying something to you or he moves something.

[Fisk]

Eliminate him.