We finished as much of the basement as possible, and this hallway was adjacent to the furnace room. Hubby used particle board used for cabinetry, and paneling to make a custom unit for the narrow hallway. He pre-assembled a bookshelf unit to fit the space, cut out the wall (not load bearing), installed the unit (he did brace it into place somehow), and trimmed it out by using lightweight fiberglass trim and heavy-duty velcro. It looks like a custom unit. To work on the furnace or water heater (on the other side), this unit would have to move out of the way. So, we can just take the trim off, pull the unit out, then put it back when we're done. I thought it was pretty slick of him to figure out.