Non-Standard House Style refers to unique properties in the market area, including log houses, earth sheltered housing, dome houses, houses with lower than normal ceiling heights, and other houses that in the Appraiser’s professional opinion, are unique.
The Appraiser must provide a comment that the non-standard house style appears structurally sound and readily marketable and must apply appropriate techniques for analysis and evaluation. In order for such a property to be fully marketable, the Appraiser must demonstrate that it is located in an area of other similar types of construction and blend in with the landscape. The Appraiser may require additional education, experience, or assistance for these types of properties.
For additional information see Handbook 4000.1 II.D.3.c.vii.(C) at https://www.hud.gov/program_offices/administration/hudclips/handbooks/hsgh