In NC the unit measurements for condo sq.ft. are based on exterior wall dimensions... hope that helps some.

I would tread carefully and NOT use the link you provided. you can find the code at this link it is longer and a little hard to translate.http://www.dgs.ca.gov/dsa/Programs/progAccess/acce...Also it is important to keep in mind that the parking requirements as far as quantity for accessible stalls is less for multi family than commercial (dimensions are the same)You may be interested in getting a CASp report for your property the report will tell you exactly what you need to bring your property into full compliance and certify it.

This lays out the dimensions and the details of the property.

@Nick Barlow The dimensions of the buildings needed to be within some tight tolerances to work around easements, which meant that an off-the shelf design wasn't going to work.

This entire 10 wide strip is physically owned by the City of San Diego...the dimensions can vary (the example below is an 18' dimension), and the conditions may not be exact, but if the meter is within this area then it isn't encroaching on your lot at all.

I know a home owner who was asked to send pictures; they sent awesome pictures, sketched a layout of the property with dimensions to help the appraiser understand the layout and even sent some comps.

I have beenable to get creative for a few people and do a SFR plus a separate small 1 Bdrm guesthouse, but that will depend on the dimensions of your lot.  

Provided, however, AM radio, FM radio, and television towers and associated facilities may, in conformance with this subsection, be repaired and used as before, so long as tower dimensions are not increased, regardless of the degree of damage.

Is he somewhat right and I am senile, or is he in some other dimension?

You checked the size with her, it is a comparable unit (dimensions are different, but the wider one had ice maker which took up space) and she was fine with it.