On a basic survey, they will be looking for obvious issues that will impact on the future potential value of the house. You have agreed the market price, they will be checking to see that there is no impairment to that. Your mortgage lender needs to know if they will recoup the mortgage money they are paying you and that the figures stack. They will check house values in the area to ensure that you are not paying too much. Its not a condition survey or a full valuation survey, just a check
