County assessor valuation vs. comp data

[Jared McNeel]

Hi everyone, 

I am looking at a rehab property and did my own comp analysis with comps near the subject property and came to a overall market valuation of 225k but the county assessor has only 174,500 for 2017 market valuation. I was having trouble finding '17 comps but a property that is almost an exact match to subject sold in '16 for 212K. Overall valuations have risen since '16 in my area so I belive it's > 212k. Can anyone explain the disparity in valuations? I want to make sure to get my numbers right if I will be making an offer. I am still very new at RE investing.

Thanks to anyone willing to pitch in!