[quote author="graphrix" date=1217641249]What happens with permitted work is the tax assessor gets the info to up the taxes, but the planning dept. doesn't send that info to the recorder (I think) with the new square footage. So Redfin/MLS and even title sources may not have the updated square footage. Here is the issue with that... if you are buying a place that shows 785 sqft. on title then the lender will need proof that the additions were permitted or value the home at 785 sqft. You or the title company will have to pull the permits and update the title to show the new 1785 sqft.
As for unpermitted additions... as I said before the lender will see the square footage on the title, and the ethical appraiser will appraise the house only on the permitted sqft. The appraiser must appraise the house as if the additions never existed. You can imagine what you think a 1785 sqft. house in SA will be worth when only 785 sqft. can be used for the appraisal. If you want a house with unpermitted additions then you need a contractor to take a look at it first, and assess what needs to be done and what they expect the building inspector will want done. Then the contractor needs to open up any areas where there are water and/or gas pipes, HVAC, and all the electrical work, plus some structural work for the inspector to see. If the building inspector just got back from a weekend in Napa after his girlfriend said yes to marriage and the work is up to code or easily fixable to bring it up to code, then you are good to go and it shouldn't cost much. You can use the cost and time to lower the offer price. If the inspector's wife just left him for his brother, and the work is no where near code and can't be updated easily, then expect a full tear down. A tear down and build up will cost $250-$350 a sqft. depending on the work and materials. Be careful on older homes in SA and CM that will need to add a new electrical box to handle the additional electrical work, that alone can set you back $10k.</blockquote>
Our Paso home had a box from the early 60's that was an upgrade from the '40's. We upgraded it to today's standards, moved it outside, moved a power line that was grandfathered in, but still dangerous and grounded all the outlets in a 1,841 sq/ft home for a grand total of ~$3,500. Is there some wiring that these 1950's homes would need that bring it up to $10K?