When you buy a house, or even a banana, you are supposed to do this: due diligence. How “diligent” you are lowers your risk in the purchase, and determining what is “due” forms the list of questions that need to be answered. In the case of a banana, your due diligence is simple – if fruit flies are circling, you’ll pass. For a real estate investment, conducting thorough due diligence using trusted experts is a must. Even then, there are always things that can be missed. But, the large items – the roof, HVAC systems, etc. – should be looked at carefully.