There are a couple of key issues that you need to know.
First, the county Assessor's office uses data that comes from another source. In most cases the local department of Building and Safety. The permit on file contains the square footage as noted by the builder.
Second, the Assessor's office can also opt to use a different third party, such as Data Quick. Data Quick buys the data from another party, a company that also gathers the data from primary sources.
Third, the data provided by the Assessor's office is only as good as the raw data, and those that input it. Many assessors office now use Geo-coding for lot size, purchasing the data from sources that help create maps and GPS mapping systems.
To sum up, is is common to have descrepancies in lot size the building living area. In most real estate literature or website the Realtor cites the source of the data. In most risk management seminars Realtors are urged to have buyers verify with a competent third party the lot size or living area if they have a concern.
You should know that technically the living square area is measured on the OUTSIDE of the property, so the living area measured is almost always less when measured from the inside. Also, that area excludes garage and unfinished basement space.
So far as you condo goes, I suggest contacting the Dept. of Building and Safety and ask them for copies of the building permits. That should give you a good start. I would not automatically suspect fraudulent actvitity by a Realtor.
When was the condominium established? More than likely the public records are based on the unit floor plan that should have been attached to the first deed out. Sometimes changes are made that are not on record and won't be public until a physical assessment is done. If you want to determine the difference between the public record and your measurments you should find the original floor plan at your local registry of deeds.(This could be done on line depending on the age of the condo). If I can be of help you can contact me and I will do what I can to assist you.
There isnâ€™t anything unethical with the way it was represented when you bought it. If they had represented that the square footage source was the public record or the assessorâ€™s card, than that would pose a problem. If you bring the town in to re-measure, you may run into some problems with your neighbors if you decide to stay for any reason. A 25% difference is significant and may prompt an increase in taxes for your unit as well as others. In your own listing, just be sure to represent your source as measured as the seller did that you bought from.
Best of Luck!
Actually, you would prefer to have more than less sqft. I would not suggest going to the assessors dept, because then you would be charged more taxes, ultimately, because you have more real estate.
I would talk to your Realtor, a professional and experienced agent in your area. She will re-measure and put the higher sqft on the listing sheet, web sites... Some Realtors will do a floor plan too.
This can be easily explained to a new buyer and they will not be disappointed by the discrepancy either.