Old loft conversion

[Hgrove]

Has anybody had an old loft improved/enlarged? Some friends of mine have in their house an old loft conversion which does not make the best use of the space and may also not meet safety regulations.  They contacted two loft conversion companies both of which said the only way is to rip out what's there and start from scratch.  I suspect these companies just did not want the work or were not confident about being able to handle it. I would be grateful for info. from someone with experience of this sort of project.