What is the difference between a mortgage valuation and a survey?
They serve completely different purposes, and assuming the first covers you for the second is one of the most expensive mistakes a buyer can make.
A mortgage valuation is for the lender, not for you. Its only question is whether the property is adequate security for the loan — is it worth roughly what you are paying, and is it of a type the lender will accept. It is often a drive-by or a desktop assessment using comparable sales data, and where a valuer does attend it may take twenty minutes. You usually pay for it, which is why people assume it protects them. It does not. It is not a condition report, and the valuer owes you very limited duty.
A survey is for you. You commission it, and it reports on the condition of the building. In the UK the main levels are:
Level 1 (Condition Report) — a basic visual assessment with a traffic-light rating and no advice or valuation. Suitable only for new or recently built conventional homes.
Level 2 (HomeBuyer Report) — the common choice for a conventional property in reasonable condition. Covers visible and accessible defects, with advice on repairs and, in some versions, a valuation.
Level 3 (Building Survey) — a detailed inspection appropriate for older, larger, unusual or visibly troubled properties, or where you plan major work. It investigates construction and defects in depth and explains likely causes and consequences.
Why it is worth the money: a Level 3 survey typically costs several hundred to well over a thousand pounds and routinely identifies work costing multiples of that, giving you either a renegotiation lever or a reason to withdraw before exchange.
Neither type lifts floorboards or opens up structure unless separately agreed. Specialist reports on damp, timber, electrics or drains are commissioned separately.