As the vendor cannot produce any paperwork and the council have no records it would seem logical to assume that the loft conversion was carried out without the correct authorisation. This really should set alarm bells ringing and you would be taking a huge risk in buying the property in that you may face more problems when you try to sell at a later date.
Some buyers do take out insurance against the work being illegal or defective although of course this doesn?t make the problem go away and it still needs to be addressed at some point.
It is possible to retrospectively sort out unauthorised work by applying to the building control office for a regularisation certificate. The good news is that quite often very minimal work needs to be done to bring the work into line with building regulations. Unfortunately, it can also unearth some serious problems.
As more people become aware of the building regulations we are seeing more and more house deals breaking down because the vendor cannot supply a final completion certificate. It is a big risk to buy a property with a loft conversion that does not have the proper paperwork.