Step in floor to define an area

Think it's a great idea. Have two steps down the the living area myself. Nobody has ever fallen. Not even babies or toddlers. It actually helps as it slows them down. They can't pick up huge speed running around and as it's only two steps it gets them used to stairs in a safe way. Other half was on crutches for a bit a while back and they didn't cause issues either.

I wouldn't be for a dropped ceiling bulkhead tbh. You're making the separation between the spaces feel smaller, rather than steps down making it feel bigger.

It depends a lot on layout. Separation of spaces can be achieved easily by different floor finishes or other architectural features depending on layout. But personally I see nothing wrong with steps used to separate spaces (though once they go longer than 4m other options should be looked at as you're then potentially losing a lot of valuable floor space to accommodate them).

We have a similar sized space - it's 17.5 meters long x 7 wide and we have it broken into 3 distinct areas : Sitting room, lounge and kitchen area. Due to the older part of the house we needed RSJ's installed so we have 2 resulting dropped bulkhead breaks in the ceiling area which acted as a natural boundary to define the 3 areas. We had no choice as the RSJ's were essential but work well in our case. The drop is less than 6 inches as we have suspended ceilings to ensure they are level (70 year old timber work was slighty off the level).

As an earlier poster suggested, the use of floor coverings can be used effectively. We did this with strategic placement of furniture to define the 3 key areas. We also went for a higher 10 foor ceiling in the new part which houses the kitchen. We painted everything white initially last year but painted the sitting room a different colour this year and it really plays a trick on they eye to make it appear as a completely separate space.

Personally steps would not be for me. It creates a hard break that you are stuck with forever and in my experience, 1 or 2 steps become a right pain over time. Did you determine how much extra this will cost?

I would vote against steps too. I would hate the idea of something that might restrict the layout of my rooms, and I think the risk is there for elderly visitors etc. It also makes the house less accessible (to people with disabilities or those who use wheelchairs or walkers). It would also annoy me having to go up and down, up and down while serving food from the kitchen or setting the table etc.