Appraisal came back with 10% different SQFT than listing

[Account Closed]

Hi,

I'm buying a single family house. Listed as 1,566 SQFT. The appraisal came back as 1,419 SQFT (147 SQFT difference). That's almost 10% and I think it's not negligible. 

Need advice and tips on what I should do next? Should I renegotiate? Is it going to affect me when I sell the house down the line and now I have to list it as 1,419 SQFT. Because when I was shipping for houses I was filtering out anything below 1,500 SQFT. 

If seller doesn't agree to reduce price, should I just back out of the deal and try to get my earnest money back?