Balterio have a fabulous laminate floor that would be suitable for living spaces as well as bathrooms - it's called 'loft white' and has a lovely neutral rustic feel:

Extensions are a great way to tranform a house into more friendly living space. Bi-folding doors, a nice big dining table in the middle and some quirky scandi furniture look amazing in building extensions. Tara Taylor
Project Manager
Essex and London Construction, Basements, Extensions and Loft Conversions Limited
tara.taylor@essexandlondonconstruction.com
www.essexandlondonconstruction.com

You've got some tricky dimensions to work with there. So before you go ahead with a design, you may wish to contact one of the Concept planner's on here, who will help you see where to put things, work out the walk room needed around objects and help iron out the flaws before you build. Karen at OnePlan comes highly recommended on here. There are a few points to look out for as I see it. The width that you have left over from Bathroom wall to outside wall of 2887 isn't that long. A bog standard king size bed is usually just over 200cm with the covers and may be more. That wall also, isn't particularly wide, therefore, if you wanted bedside tables, it could be tricky to use that space. So, putting the bed on the back wall, which will probably look nicest has other problems. Easier to show in diagrams ( hopefully ). I can't see how big the nib is at the top where i've put a couple of Chests of Drawers . I know we couldn't manage without them. I feel the large window is too big, and if you're going to put wardrobes on that wall, then you need to make sure the window isn't to large and that you leave a big enough gap either side for not just the wardrobes, but also for any window coverings. You don't want to be pushing curtains in to wardrobe doors and not having enough room for poles. I'd make the bathroom a little smaller to get better walk room in the bedroom. Unfortunately, Architects rarely think about furniture placement, I personally think it's paramount in considering the sizes of walls, windows and how to live in a space. However, i've done many a build in my time, so I know the pitfalls. Concept planners will help you with all of these problems.

Always go back to the building company first if you are not happy with it and in writing. Has the whole project been finished and you already have the Building Regulations Certificate? Either way best to go to your builder as as soon as possible, agree with some earlier posts that perhaps the measurements were wrong. Just wondering if they could trim it back neatly? Ours has been done like this so not sure if they could trim it back in a similar way or at least to the step otherwise it would be a trip hazard ( and yep, I still haven't got round to painting it yet! ). With regards to the plastering on the curve, it probably needs some filling and then sanding down before painting.