Surveyor
A surveyor is a person qualified by the Royal Institution of Chartered Surveyors (RICS) to carry out valuations and surveys of properties.
Your mortgage lender will require a valuation survey to be carried out to make sure the property is actually worth enough to cover the mortgage you wish to take out. It's in your interest to have a more detailed survey as well which may disclose structural defects which may not affect the mortgage offer but could put you off buying.
You may want a structural survey which can be quite comprehensive or a less inclusive survey which is commonly sold is a homebuyer's report.
Get professional help from a qualified independent mortgage advisor and see how much you could save on your mortgage payments. There's no obligation, just plain good advice.
See also: Financial Services, Mortgages