Make the new wall accommodate the curve please. Much easier than removing the cove. In addition, it's reversible; the next person may not like your idea.

Thank you and I appreciate your thoughtfulness on ease, but the new wooden facing for the closet cannot accommodate a curve. And as the homeowner, I'd like to fix the issue as it has really bothered me the past 12 years.

Have you considered scribing and cutting the wooden facing?

Is there something behind the curved edge? Wiring?

I appreciate the alternative you offered, but I'm still wanting to understand how to straighten the curved edge of my ceiling, even if it's difficult or costly. I don't believe the curved edge is covering anything.

If you are going to take the curve out of there, it would make sense to me to engage a drywall contractor to do that work. They will test first by pulling a portion of the curve out to see if there is anything odd behind it (like a gas pipe, etc.) Then they can remove the curve by taking out drywall if necessary and adding back that upper section. They will then tape and mud it. They might have to take out a foot on either side.

Thank you so much!

Are your walls drywall or plaster?

Not a big deal if the walls and ceiling are drywall. Whole different story if this is plaster and wire lath. The older the bldg, the more likely for it to be plaster.

Finding someone willing to take on a small job like this--if plaster, a small nasty job--is going to be difficult to next to impossible, if you want it done well. Scribing the closet build to fit would be much easier. If the closet is built starting from a corner, then you are looking at only one scribe junction.

BTW, this is what you call a 'coved' ceiling.

Thank you! I am leaning towards the walls being plaster and I'm 95% sure they are covering a brick wall behind them, as my living room has the original brick walls from 1903. The previous owner did the updates himself, and the work is very shoddy and uneven including the coved ceilings.