It will depend on the type of loan you're using. On an FHA or VA loan, the appraiser is required to provide more scrutiny than on a conventional loan. I suspect you're probably talking about an FHA loan, where the appraiser must cite health and safety concerns. I know that there are guidelines they follow, but some of it is also somewhat subjective, so in the end, a lot really depends on the appraiser's personal evaluation of the property. Certain things are going to be called by every appraiser (i.e. a tarp on the roof, a clear trip hazard outside, wires hanging from the ceiling, broken windows, etc.). But other less obvious items may be called by one appraiser but passed by another.
An appraiser can also recommend certain clearances (i.e. roof, termite, plumbing, heating) if they see a condition that warrants inspection by a professional. So even though there's no tarp on the roof, if this is the only house in the neighborhood with an older roof and there are water stains on the ceiling, the appraiser's likely going to recommend a roof clearance from a licensed roofer (which essentially means put on a new roof or you don't get the loan).Similarly, if there's a wad of extension cords running across the floor suggesting that the home might not be wired to adequately to accommodate everything that's presently being powered, the appraiser may likely recommend that a licensed electrician inspect and sign off on the electrical system.
So, yes, with an FHA or VA loan, there are minimum property standards.Your lender should be able to provide these to you. Or you probably can find them on HUD's/FHA's web site. Or on the VA's web site.
Essentially, the appraiser is the lender's eyes and ears, so he/she is obligated to provide both an estimate of value and an evaluation of those conditions which could affect that value. While an FHA or VA loan definitely demands a higher level of scrutiny by the appraiser, even on a conventional loan you could still end up with appraiser-noted conditions. But these are probably going to be clear and obvious serious health & safety hazards -- things that even the casual observer would easily recognize.
Best of luck!
- Rod Herman