In Scotland the seller has to provide a professional survey available to prospective purchasers tho’ you as a buyer are still advised to get your own and in any case a mortgage provider will want one. Very dodgy to buy without your own survey. I think it is a criminal offence for the seller to avoid mentioning any problems and the they could face substantial fines but I am not too sure on this. The only house I bought was nearly 40 years ago so I have no recent direct experience.
The law in England and Wales is different from that in Scotland. In England and Wales, it's buyer beware - that's why purchasers have surveys done and why they ask questions of the vendor before the sale becomes binding. A lot of people would have a criminal record if what you say is true.