Selling family property, having some issues with official square footage.
My parents are trying to sell a commercial building, the issue is that the city seems to think the building is 2700 sf when our rough measurements show that it's closer to 4200. We did not add anything on to the building while we owned it.

We requested  structural plans from the city but they don't have anything on file. 

We are at a loss as how to properly show the actual SF, hire an architect or a draftsman? The City isn't being very helpful.

Any guidance is appreciated
[{"id": "iu31jzs", "text": "What does your broker say? Why not just list the actual square footage and not care what the city says?", "replies": [{"id": "iu33pj9", "text": "So, the Tax assessor believes it's 2700 SF, do we not need to \"Prove\" it's all properly permitted and such?", "replies": [{"id": "iu3533x", "text": "As someone that would be looking to purchase, I'd see that as a win. Lower taxes. But I would put it in my underwriting at the hirer tax rate. I wouldn't sweat it.", "replies": [{"id": "iu4b80c", "text": "This is the correct answer. You can advertise that its whatever SF you believe to be correct based on your own plans or measurements and buyer can get a survey or measurements done of their own if they want to dispute or verify.  Either way, the city/appraiser thinking its less SF is a win that equals Lower taxes.", "replies": [{"id": "iu57h8v", "text": "I'm starting to understand, thanks for the input guys. I appreciate it.", "replies": [], "depth": 5}], "depth": 4}], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "iu31nxw", "text": "When you say the City, do you mean the tax assessor?", "replies": [{"id": "iu33jga", "text": "When we search the Tax assessors website for our property it shows the 2700 number.\n\nSo, my understanding is that we have to go to the Tax Assessor's office with \"Proof\" to show them them the correct information before we can put it up for sale.", "replies": [{"id": "iu33t8s", "text": "I can\u2019t speak to your jurisdiction, but in mine what the Tax Assessor has in its records is 100% irrelevant to how I market a building for sale.  Get an architect to measure using the BOMA standard and then market what it actually is.", "replies": [{"id": "iu456m6", "text": "I do commercial appraisals around the SE in different counties and probably have only seen these two square footage numbers match up a handful of times. I always go by what\u2019s been provided through a survey/building plan/leases over the assessors", "replies": [{"id": "iu57l59", "text": "I will pas this along, this is what I was hoping was the case! Thanks again.", "replies": [], "depth": 5}], "depth": 4}], "depth": 3}, {"id": "iu5y44j", "text": "Call them to remeasure.", "replies": [], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "iu35ot8", "text": "There are companies that measure and draw commercial buildings via autocad, and can stamp them per BOMA standards.  Probably $0.15-$0.20 per foot.  Take that to assessors office, and they should accept and record the correct size.  Keep in mind how you measure, and BOMA, will be quite different.  Likely somewhat in the middle of what's currently assessed and what you are expecting.", "replies": [{"id": "iu57b4y", "text": "oh perfect, I was afraid of having to pay an architect to do it. Thanks!", "replies": [{"id": "iu69owu", "text": "Only - don\u2019t turn it into the city or you will pay higher taxes.  You should be able to list it at the official measurements and the city can go after the next owners if they want more tax revenue.  You tried to get them to correct it - I would not pay and force them to.", "replies": [], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "iu44j7d", "text": "Get it measured yourself and let the city have their lower measurement and you can keep your lower taxes.", "replies": [{"id": "iu57dlm", "text": "This seems to be the consensus, thanks for the advice!", "replies": [], "depth": 2}], "depth": 1}, {"id": "iu56h79", "text": "I just went through buying a commercial condo and the square footage is 10% in dispute.  If I were going to sell my commercial condo (sometime in the future), I would pay someone to use the BOMA standards and have a set of drawings before I made an advertised claim of square footage.\n\nI agree though, I wouldn't update anything at the assessors office and would have 3rd party dimensions to provide to any interested buyers.", "replies": [{"id": "iu57qu8", "text": "BOMA. got it. I will look for someone who is able to do so today, thanks!", "replies": [], "depth": 2}], "depth": 1}, {"id": "iu6vwni", "text": "The best thing to do is fully disclose this to all prospective buyers. Sell it with a clause saying that the buyer assumes all risk.", "replies": [], "depth": 1}]