It usually requires threee pics...1 of the front of the house, one of the number of the house, and one of the street scene...then run a CMA of comparable SOLDS in the reaired value condition, and use a balanced average of the solds vs the subject to come up with a valuation
If on your "drive - by" yu happen to notice the place has been abandoned, you can can peek in the windows and try the door. There may even be a lock box on it already and you might be able to get interior access anyway. The previous listing (if any) may have interior pictures and possibly description of defects. You can certainly guess if there are broken exterior windows, trim, rotten roof, driveway buckling, dead landscaping, fallen down fencing, graffiti, green or black swimming pool water. etc.
As far as the interior is concerned you could speculate that due to the awful condition of the exterior, that it is likely that there are problems on the inside.
The companies understand the limitations of the "drive by" BPO. Ask the company for guidance on what condition you assume the property is in. If it is listed, go off the listing remarks and pictures. Be able to stand behind your report and how you arrived at your value. Repaired value can only include the exterior for a drive by...was there dry rot? Broken window? Did the roof have a 10x10 hole? Etc...
Looks like you'll have to use comparable recent solds, past appraisals and tax records, and estimate the worth based on perfect condition and 'as is'.
What a pain, though.
Sounds tough. I don't think you can get closer then within 10% of market value by just driving by. I'm always surprised by what someone, sometimes sitting in another state, can come up with for us to do.