In message , Tim writes
Not quite, I think you are trying to put an incorrect 'spin' on it by slapping on this 'unprofessional' label. It seems to imply that valuing a house is like obtaining the result of a mathematical equation, which it most certainly is not.
A formal valuation for mortgage purposes 'should' come out at the same figure if done by the same valuer on the same day. The answer to the 'key question (previous posts) will depend on the loan to value ratio.
A survey for the purposes of sale or purchase are different things.