Too much of a feature becomes a distraction. 70's / 80's brick interior houses were great then but are clearly dated now. One feature wall with the other walls in smooth plaster can still work, provided you address the feature wall as such, by not cluttering it with stuff. Try keeping the furnishing minimal and selected feature wall type dressing. hopefully this way you feature wall will look stylish. Hope this helps. Alfred Botha. www.gapdesign.com.au

I agree with both your painter and your Google result. The issue is something that has soaked into the surface of the old wall, particularly as you had an odd result when cleaning. You can’t expect the painter to sand and paint as part of the original job but they may be able to offer advice and action if you’re prepared to pay them. If you want to DIY I’d be sanding the wall and trying some stain locker undercoat.

quite possibly, that was going to be my next solution! heading back there in a moment to check it out. the existing tiles have been layed quite nicely/flat so i dont think tiling over would be an issue

Thanks again everyone. I totally agree with so much of this! We hate the curtains but had to put something there while the place was tenanted. My plan so far is for very discreet blinds, if anything. There is a bench seat going in under the stairs, an art gallery up the stairs and wrought iron balustrades. We’re deepening an existing window at the top of the stairs to throw extra light down the stairwell and into the dining room. All the existing lights will go. After that, we’ll revist the paint!