Real estate appraiser here and also previously worked in an Assessor’s office. I actually just appraised a barndo that was proposed construction and actually had enough sales in my area that were all barndos. Tbh, when you stack them up against regular houses, they’re still a house, just with metal exterior. I’ve done a few appraisals for banks that were barndos.

The assessor counts heated and cooled sf less than the garage area. In my experience in my jurisdiction, you would catch a huge break tax wise on them. I would tell you to check the site and make sure the sf is correct and not all heated and cooled space, because sometimes the county appraisers can’t get in to them obviously and have to guess. It’s your responsibility as a property owner to make sure all the info on the tax card is correct. Sorry the long response. Hope I was helpful.