You have two very different styles going on here, which is why this doesn't work, and why what your designer suggested wouldn't work either. If your kitchen is separated from the rest of the house, the easiest thing to do might be to just remove the white crown from the kitchen.

I think that the plasterboard should continue above the cabinet, so the corner will look continued.

( wood cabinet must not reach the ceiling, I think )

Your designer is correct. Your builder just doesn't want to correct his mistake.

I agree with your designer, although I would not stain the ceiling molding to match the cabinets but paint it white so it reads continuously around the room. If replacing the flat trim is too complicated at this stage, a pragmatic solution would be to paint it white to match the ceiling molding. In any case, it's important to keep the ceiling molding/flat trim the same color as it wraps around the room so as not to snag the eye.

Personally, I think I would just eliminate the white crown. I never would have used it in the first place with dark modern cabs.

Another vote for removing the white crown (traditional) from what appears to be a modern kitchen. If it extends into adjacent spaces, then you need to pick from the various awkward solutions -- in that case, perhaps easiest to leave it for now, if burned out, and revisit in a year.

Yup, door n°1. Thanks for the visual PPF !

thank you for all the feedback so far. I should have clarified that this is not the kitchen but a built in nook for computer and TV. The kitchen is white and the crown molding matches well. This nook if off the kitchen but around a corner so not immediately visible. We talked about not doing the crown molding in that area but we couldn't come up with a good breaking point from the rest of the house. We had talked about taking the white molding across the top of the dark cabinets but I didn't know if that was an acceptable design option. I see PPF has posted a rendering of it and others are suggesting it. Here we are trying it out. This might be my favorite option because of the clean lines, I just couldn't find any picture on line of something like that so i didn't know if it was taboo.

Now seeing what you have, I prefer continuing the white molding like you're showing. It's really the only good solution and will help tie it all together.

BTW: What is the make of your fan as that's exactly what I'm looking for for my studio?

I would have suggested this.

yes, that would have been a great option. now that we are into it I can think of several things I wish we would have done instead. I'm sure you've heard that one before. :) I'm thinking that adding the white crown now would at least give a suggestion of this rendering and be the least jarring of all the options.. Do you agree? and thanks btw, for the renderings. very helpful.

cpartist here's the ceiling fan:

https://www.amazon.com/Kichler-330243MWH-Bowen-Matte-Ceiling/dp/B0186GBA30/ref=sr_1_13?ie=UTF8&qid=1498946617&sr=8-13&keywords=kichler+ceiling+fan+60+inch

with this controller: https://www.amazon.com/Kichler-Lighting-337012WH-Ceiling-4-Speed/dp/B001L8Z6C2

It doesn't look right to me with the crown over the cabs. It ruins the look of the entire cabinet. Especially with that style of moulding.

Thank you amyclove. Definitely going to order it!

I like the look of the white crown for a continuous look, but it gets really squished looking with the upper doors not having any breathing room. Not much you can do about it now ... unless you want to spend more money and time.

I agree with suzyq and chispa, in an ideal world the cabinets would have a horizontal filler in wood above the doors of approx. 2" to finish them off before the molding. Alternatively, PPF's latest perspective with the molding set forward may offer just the visual distance / breathing space needed between the cabinets and molding. I'd go with this pragmatic solution. No project is perfect and details you may be focused on now when the space is empty may be water under the bridge once you have moved in.