Experience of buying studio flat in Paris?

[wendy]

I dream of getting a studio flat in Paris to stay in for holidays only and as a staging post for trips further afield in France.  I have seen quite a few already and am going again soon to view more.  I read this Forum every so often to pick up tips but have seen only one post about a Parisian studio (query about its having been let by the agent without the owner's agreement). 

Those I have seen have been converted from bare rooms, so shower, wc and kitchen area installed fairly recently, often apparently by the person who is now selling.  How do I ensure that any regulations governing this kind of installation have been observed?  These properties evidently move very quickly so I get the impression that French buyers are not perturbed by the legality of the conversion work - so do I need to be?  If I wanted to be sure, I assume I could ensure the compromis de vente included a provision that the work done on the studio be checked with the relevant authority, and that if it was found not to comply with any 'normes' in place, the sale could be renegotiated or cancelled - is this correct?

Has any Forum reader got any experience or light to shed on the idea of buying and owning Parisian studios generally, or about the shower room / kitchen installation in particular?

Merci à l'avance

Wendy[:)]