The short answer
Beyond condition, understand planning risks, legal constraints, environmental factors, and lender appetite.
A viewing tells you about the state of the property, but not about the things that most often derail a purchase later: what's planned nearby, what's attached to the title, and whether a lender will actually finance it. Checking those before you offer puts you in a stronger position either way.
Why this matters for your purchase
This is the kind of thing a PropM8 Scan is built to show you early, before solicitors, surveyors or lenders are involved, while walking away still costs nothing.