Your offer is not going to be $173.98 per square foot. So worrying about just how many square feet may not be a good use of time and energy.

Some measurements are outside edge to outside edge. Those measurements will be larger than if you measure the interior of each room and add them up.

Make your offer. If it doesn't appraise then you can renegotiate.

We are not interested in renegotiating. Even picking 100/sq ft that is a $50,000 dollar difference.

Here is an article with some sqft calculation details, hope real estate agents on this forum could verify and validate the approaches.

https://www.homeadvisor.com/r/calculating-square-footage/

Of course using the outside dimension of a house to calculate sqft is different from adding all the square footage of each room, because sqft of thickness/length of interior walls are not included. In other words, using adding interior rooms sqft approach, the more rooms the less the sqft.

I would find out exact details of the property including square footage before making an offer.

Thanks, I know how to calculate the square footage and we have already measured so know the values, but what I'm wondering is about the unconditioned vs. conditioned spaces and how they are treated in an appraisal.

Ie is a finished, but not connected to any house system ac/heat and currently not having a separate source of that counted the same as the rest of the finished sq footage. No matter what the house is missing quite a bit of square footage.

I find the use of the terms conditioned and not conditioned confusing.

homechef59 - thank you that is just what I needed to know. Since we are in the south I wonder if heating could be considered optional too.

I now know where the missing square feet could be. Looks to me to be en error on the county appraisal districts part as they have that listed as the upstairs and there is a room vaulted that matches the size perfectly of the missing square ft. I checked with CAD office and they don't count non-heated space the same and we would just need to call them to come in and re-asses if we purchase the property. They did say if what I was describing was correct then they do have it wrong as they don't count vaulted ceilings as sq ft.

My calculations matches within a few sq ft. on the down stairs now too if I remove the laundry room.

Oh for anybody that may find this post at a later date I also found these blog posts that may be useful to someone in the future.

http://birminghamappraisalblog.com/appraisal/four-areas-the-appraiser-will-not-include-in-your-homes-square-footage/

http://birminghamappraisalblog.com/appraisal/can-a-sunroom-be-included-in-the-gross-living-area-of-a-home/

lyfia,

Heating would not be considered as optional. You might have an argument in Key West.

Obviously, cooling is optional. There are many areas of the country where EVERYONE has air-conditioning. If you didn't have it and everyone else had it, you have a marketability problem.

Thank you homechef!