Is garden unit with only 1 egress legal in Denver?

[Ryan Monty]

I visited my brother last week who lives in Denver proper and was a little shocked when I toured his garden apartment for the first time. He lives in a converted SFH where there is a side door that leads into a stairway landing. Going up the stairs they simply built up a wall so you can no longer access the rest of the structure. Going down into the basement there are no other doors, only a few very small windows that would be impossible to crawl out of in the event of a fire. The ceilings are also very short, like around 7 feet high. On top of all this, the management company that manages this building has been jacking him around a bit in the short time he's lived there.

My question is:  can this possibly be legal in Denver?  In the municipality I live in, this would be immediately shut down as a safety hazard.