Judith Scott said it, "Location", so let me say it MY way.
LOCATION
LOCATION
LOCATION
For instance, where I live, MANY homes have no water, no sewer, no phone, no natural gas and no paved roads. By 'many', I mean thousands of homes. And some of these homes are literally mansions whiles others are dumps.
When I bought in the area, I demanded these things. I could have bought one more mile north and would be one of those homes. I am one of the furthest houses from the city water plant so I have to have a water pump under my house to add enough pressure so I can take a shower. But I am on all city utilities.
As for rentals, I have one rental that uses trucked in Propane and I will never buy another one, it adds several hundred dollars a year to my expenses. All my rentals will have all main city utilities.
In addition to location, the house needs to be built to handle the area it is in. Single paned windows in a cold climate are not good. Stucco in cold climate is also not good. I have seen a three year old house in the Rocky Mountains start losing its stucco from the freeze/thaw cycle and in six years have to be re-stuccoed. In hot areas, a good roof, good AC and good ventilation are necessary. I have seen cheap, asphalt shingles get destroyed by hear in just a few years. When I was a Realtor, we used to joke about "toilet paper covered in Elmers glue and sand" being the quality of roofing used by some builders, especially out in Moreno Valley, California.
A good location, quality craftsmanship and a fair price. What else do you need?