Every rescue is different. Here are a few things I look for.
Is the body of water fenced off
Does the house have steps, how many? ( older dogs may not be able to do steps)
Yard fenced securely.
Verify other animals are well cared for.
See where the dog will spend his time when you are home & when no one is home.
These are just a few so you get the idea. A lot depends on the dog you are adopting & what his needs are.
It is so nice to meet the potential new family face to face & make sure it is a good match for all.
Good luck!!!!