Recently we have appraised a property with an accessory dwelling unit (ADU) for a purchase. The property was listed on MLS with the combined square footage of both the primary dwelling and the additional dwelling unit. The primary dwelling was approximately 1,000 sf with two bedrooms and one bathroom. The additional dwelling unit was approximately 7oo sf with two bedrooms and one bathroom. The listing had the square footage as 1,700 sf with four bedrooms and two bathrooms.
First off, two separate dwellings do not equal one dwelling of combined square footage. The ANSI Z765-2013 standard (Method for calculating square footage), Fannie, Freddie, and FHA require this to be appraised as a 1,000 sf home with an additional dwelling unit. It definitely aids in the appraisal process if the listing accurately describes the property. The comments did indicate there were two 2/1 dwellings, but did not describe the size of the primary dwelling.
I was asked if this property could be compared to duplexes. The answer in this case was NO. There was adequate data of single family dwellings with additional dwelling units in the subject’s neighborhood which had identical zoning to the subject.