report on damp in residential property

I am looking for someone with expertise in damp to investigate a damp issue in a residential house. The issue appears to be localised to one area, so needs investigating to understand how best to proceed for the purpose of selling the property. The right candidate will need to examine the property both inside and out, carry out an inspection and create a report detailing the full extent of the issue and the likely repair costs so that I can make an informed decision when it comes to the sale.