Jay50 is right. Good for you on building the addition and I hope you enjoy it. I certainly don't blame you for skipping the permits but there is a price to pay when you sell. Many years ago the industry standard was "done in a workmanlike manner with materials and craftsmanship similar to those utilized in the original residence." If that was met then FHA and most lenders would allow inclusion. However, a few years ago sentiment has changed to "no permit, no count." In my county they definitely use aerial/satellite photography. Once someone noticed that addition (and we're in California and deserate for money) you could expect a notice to get it permitted.....and of course pay the fines. In most areas, the county records that are being so widely misused and abused for valuing your house when you get a loan are based on the tax assessor's records. Even if you have an actual appraiser come out, chances are the lender is going to rightfully insist that the appraiser exclude that area and any value associated with it and make a comment that it doesn't appear to pose any readily observable health or safety concerns. The no permits thing, with an addition, is a far bigger deal now than it used to be. I'd say unless it is something easily removed like the topic of the post, just don't do it.