Viewing a property with a Builder? (Help)

I was just on the phone with an estate agent regarding a house and he mentioned that five people viewed the house and then two returned to view with their builder. How does one get a builder to view a property with them or is it just these people have builder friends? I am currently looking at houses that need renovation and assumed a builder would only be interested when they know you own the property?

Is there a service or other option to find out if the house I am bidding on is fit for my renovation plans? I often find these are the good pieces of advice that are missing from renovation shows, and hence why they end up over budget.

Many will know a builder alright, but it is possible to arrange for an engineer or registered building surveyor to attend with you. A consultation on options and costs would likely cost less than a formal survey. You might even be able to do a deal with a surveyor to agree a discount on the survey should your bid be successful.