Just checked this out, but still haven't figured out all the steps. Access to info:
http://www.efanniemae.com
Look for Lender Letter 01-02 dated 3/29/02, which Announces that Fannie Mae's Selling Guide has been updated, restructured and reformatted. The new Selling Guide will be available via AllRegs Online early the week of April 15. (thats where I got lost, AllRegs Online is offering a free 90 day subscription service so the new Selling Guide can be accessed, downloaded and printed, I subscribed but can't get any further than that).
In describing the changes to the Selling Guide it refers to Factory Built Housing, Chapter 3. The part that Charlotte originally refered to is that Fannie Mae has liberalized the requirement that at least two comparables have to be factory built. But for manufactured housing, two comparables of manufactured housing are still required.
So what that means out in the real appraisal world:
If the home was originally constructed to HUD building code, at least two of the comparables are required to be also built to HUD building code.
If the home was built completely or partially constructed in a factory to any other building code, the comparables utilized are not required to be built to the same building code.
Although for practical purposes, similar properties of similar building codes, style, amenities, quality of construction, construction materials, (after location is considered) etc, etc, (no matter what type of property being appraised) are the most logical indicators of market.
So if your subject was built to HUD building code, indicated either by the red HUD label on the exterior or the letter sized map of the USA, known as the data plate or Certificate of Compliance found inside the home or by research of documents--Fannie Mae still requires at least two of the comparables to be HUD code homes also.
If someone can figure out how to access the free AllRegs let me know!