In the past I've written about using a line based family to document path of egress information. Brian Mackey with CAD-1 Denver recently shared a concept he uses for demonstrating that a stair well has sufficient clearance. He uses a railing family that has a profile to document the required clearance instead of what we'd usually use. In this example I quickly mocked up I just used a similar "guy" I'm calling Clarence, so Clarence can show the Clearance is met.
It's easy! Just create a profile family and load it into your project. Assign the profile to a new railing type, called Clearance. Assign Clarence to the Railing. Place the railing on the center line of the stair. You'll have to fuss with graphics and decide when it should be visible but it's pretty simple. To really show the zone required for clearance a simple rectangular profile off a specified height would suffice and show where no building elements should touch. A quick interference check would help catch problems too.
Cool solution Brian!