"1. If the county record is 1300 sq. ft, will this affect the appraisal result, thus affect the total loan amount determined by the bank? or will the appraisal based on the actual sq. ft. determined by appraiser? "
The Appraisal will be based on the as-built square footage. However, typically, Appraisers are not allowed to provide value on unpermitted work.
"2. Will I have a problem resell this house in the future if I choose to?"
There's no reason to suggest this above; non-permitted work notwithstanding, that is.
"3. What were the possible reasons the previous owner didn't want to report the expansion to county office? Should I be concerned?"
Typically, when a City permit is signed off the County sends a questionnaire requesting info on the project to determine a new property tax base. In my experience, many Owners have higher priorities and/or do not want to go through the time and cost of the process.
Your Realtor and Title Company should be aware of this, and advise of you of the County discrepancies.
Your Realtor should also advise you that its always the BUYERS responsibility to complete the Due Diligence and verify the square footage of the home, the permits, condition, etc-
The loan amount will be based on the current appraisal amount as determined by your appraiser.
Best advice is to complete your due diligence, and make sure your title company, mortgage company, and Realtor are all on the same page with the current condition of the property!
Nicole Fedorchek, Realtor
2. Probably.....You're concerned, others in the future may also be concerned.
3. The omission could be intentional or unintentional; and if you still have concerns, consult with an attorney.
Consider taking your own measurements and basing your decision on those numbers. As far as concerns for the future, regardless of what the tax records say, the present square footage(whatever it is) will always be there.
I would have to believe that taking the necessary permit action should be considered enough action to have the county connect the dots.....we however know this to not be the case. I'm presently working with the same scenario on a transaction. The difference between this one and ours is that we are using the county tax numbers as the official numbers that are posted on the MLS and publicizing there is a difference between this information and the actual square footage.
Good luck with your decision.
Let me know if you need anything.
Coldwell Banker Star Realty
BRE Lic #01456982