Appraisers - Appraising something with no comps?

[Melissa Kirchhoff]

Can any appraisers give me some insight about this? How would something work where someone needs to get a loan and an appraisal needs done, but there are no comps? Does this mean everything is a no-go?

My best example would be something like the first condo building in a rural area where only SFH and attached singles (duplex or townhouses) exist. What would happen in this situation?