I am nearing completing my dining room / garage conversion.

Before I dry line the last wall, I want to sort the step that is between the lounge and the dining room.  I had to have a step unfortunatly.

There is to be matching carpet in the lounge and dining room, and I cannot decide what is best at the step.

A bullnose piece of wood level with the lounge, with the carpet run over the bull nose?  Then painted wall for the few inched to the dining room floor?

Lower the dining room side of the cavity wall, and have a carpeted step midway in the wall?

I am not too sure!

I find it difficult to visualise!

Would that bull nose be flush with the wall, or jut out a bit?

Polished timber tread and riser, ( just like the bottom tread of a good many stairs ) made wider than the door opening so you can stand architrave of the tread. Line out the reveal of the door opening and have architrave off the tread.

Have a look at this

That looks about right, if you are going to carpet there is no need to rout a perfect edge, just round it over with a plane.