The USPAP standard for ALL appraisers, HUD, VA, Conventional, etc require that below grade bedrooms, family rooms or other any other finished space does not add to the square footage of the appraisal. 

An appraiser is more looking at general condition, square footage, baths, beds and comps.

The apartment units are 4br/ba and the townhouses are 4/br/4.5ba with a good bit more square footage and a small "porch" (concrete slab).

So, your extra footage would be worth $50 or so vs. comps.No permits sounds bad.

Then they can change all the information such as rent/sale amount, features, square footage, and so on.

Can you give some more specifics about the property in terms of square footage, year built etc...We can then give you a more accurate assessment of rental rates and comps, and then let you know if your yield expectations make sense.

All taxes seem unbelievably low to me & sq footage very small.

Questions like; was the job finished on time, did the company go over on their bid, how much experience does the installer themselves have (journeymen or 3rd year apprentice and higher would ultimately be best).Knowing square footage and/or having prints available if you go into an office can reduce time spent in the unit, which can reduce overall costs.

To sell you must have a valid legal description of the parcel to be sold, otherwise you are attempting to sell a non estistant parcel.In your purchase contract you need a partial release amount for any parcel that may be legally described in the future on a square footage basis.

Look up properties based on square footage, beds and baths similar to the one you are interested in.