The way measurements are taken changed in 2017. The "new" way of measuring your home contemplates only interior spaces and only measures "paint to paint". This regulation change chance could bring your square feet measurement down as much as 10%. Balconies will not be counted but you can mention them in your home description.
Given the mandatory nature of measurements, rest assured that comparable homes on the market measured using the same criteria so your listing will be competing on equal footing.