Can I procure retrospective building? I have bought a 3 bed property which have had a...

I have bought a 3 bed property which have had a loft conversion done so within theory it is a 4 bed but the general public who did it did not get building regs for it. Is this something I can apply for since I sell to formulate it officially a 4 bedroom or even worse if I do this can they receive me put it back to how it be. A velux window have also been put surrounded by which I'm pretty sure needs planning consent.
Suggest a colour?
Answers:    i would advise you to obtain in contact next to your local building control ..im a builder and am in constant contact near building control ..most are good guys and are lone too will ing to advise ..one entity for sure ..you WILLhave to change your velux into an escape windowpane ...gauranteed !
Which wall and which color for an elocution...
Depends on a lot of things (particularly in the region of re-instating to a previous condition).
How long ago were the change made (4-y- rule and 10-y-rule)

Building regs are about maintain structural integrity and fire safety. Could cost thousands or practically nought to make the loft a 'habitable' room.