the house we are planning to buy has a room in the roof which the current owner says was there when he moved in(this is true)but now that we come to finalise things the surveyor has undervalued it because he saw no paperwork for the room and says he will only amend valuation with the relevant documents.Our seller doesn't seem to have any and he moved in in 1997.Who keeps this info?If I rang the council would they have records of planning/building regs for addresses going back at least 10 years?He says he thinks the roof room was done in 1990 and is sure his solicitor would never have let him buy it without the paperwork but I am not risking it.