How to remove a curved finish from wall/ceiling

[Nellybob]

In the middle of a building project and builder has plastered a curve between the wall and sloped ceiling in loft conversion. No idea why - he didn't ask me and I've barely been home in daylight since it was done (a few days back) so only just noticed the abomination. Bottom line - the wall and ceiling are now one thing, it looks ugly, dated and will be impossible to decorate. I have no idea why anyone would have made such a design decision and it just needs to go. My question is, what's the least invasive/messy/annoying method to achieve this? Is it possible to chip out the plaster forming the curve ready for making good or will the whole lot have to come off?

Any suggestions that might make this as painless as possible gratefully received.

 

[Wayners]

Put a 3mm stop bead along a laser line and skim to that to give shape angle
Would need to knock off current plaster.
Picture will get better advice

Can be hard to get sharp lines so curved ceiling line is easier.

 

[Nellybob]

I get the need to curve the line that's actually in the ceiling where the angle is shallow - the bit that offends me is the massive curve that's been inserted between what should be the wall and what should be the ceiling. I can literally not find a single picture of a modern loft conversion where this has been done. Not one. There's no lighting on the landing yet so will take pictures in daylight.

 

[Wayners]

Raise your concern now them. If you don't like it get it sorted