Locker Room
From Homestar Runner Wiki
Coach Z's Locker Room is Coach Z's office. His office was originally going to be the showers, as seen in one of the deleted scenes for In Search of the Yello Dello.
There was a rumor that Coach Z sleeps in one of the lockers, but Coach Z states in his Character Video that he would usually "crash on [that] bench right [there]," which is proven in the toon A Jorb Well Done. Sleeping on the bench has led to his back being in poor condition.
Oddly enough, Coach Z does have his own apartment, as Strong Bad tells us in the Fan Costume Commentary, but he apparently sleeps in the locker room. The apartment's a "sty hole," though, so he might just come here to get away from having to dig out the trash covering his bed. It's also possible that Coach Z was evicted, since he seems to have major financial problems.
In Halloween Fairstival, Coach Z turns it into a not-so-scary haunted "Locka-Room".
