Why does it need a trim piece at all? Aren't the windows fully finished? If it's to try to hide the stairs from the outside view, I might just install some bottom up cellular shades there and leave them up from the bottom just high enough to hide the fact there is a staircase there.

I would worry about someone tumbling down the stairs and going through the window, however.

I like it. Looks very unique and interesting. brings in so much light.

I agree, remove it. It looks rather silly.

Was he trying to hide the side of the stair?

it would be hard to clean with the board up - I would remove or have him trim to outline the stairs-- what does it look like outside looking in and where is this window in relation to your house?

Your architect messed up the design BTW

It appears the window is new. If this window replaces an existing window, I would have suggested replacing only the window that does not have the trim piece.

I would replace the window, so that no window sits behind the staircase.

I would check with your city and county to find out what the code is. We have stairs in front of a window in our foyer and there were many requirements to pass inspection. Did you pull a permit for this work?

What is the rise and run of those? Looks too steep. Were the joists in the storage space reinforced for live loads? Design F. The whole design is wack. It needs to be changed. That detracts bigly from the home value.

I know it is a new window, but, I would have it removed and the wall redone so there is no window there. It serves no purpose except for light. Maybe a skylight would have been a bigger option for light. It looks so dangerous to me, if someone would trip or fall, and go through that window, it could be terrible. Definitely a safety issue. I really doubt, it would pass code either. Best to do it right from the beginning. Sorry.

I am thinking that piece ia code thing to cover the glass there to protect from breaking if someone slipped on the stairs. I am wondering if this was actually permitted at all.

I had an existing window and stairway in a similar configuration in a coachhouse I remodeled. To pass inspection we had to install a guard across the entire bottom half of the window, not just partially like this.

Normally anything window wise in a stairwell is required to be Tempered Glass.

I suspect unpermitted too. Where I live, codes are not all that strict, and many things get by, but, a stairway with a window like that would mean the house couldnt be occupied until it was redone.

It looks safe and fine. Don't sweat it. Paint it and install the carpet.