Granny Flat ADU - Discover the Granny Flat - Auxiliary Dwelling Unit. Keep your loved ones close by and embrace sustainable living with Portable Cedar Cabins' brand new "Granny Flat Retreat". This meticulously crafted, wood-crafted cabin is designed for those who desire a connection with nature without sacrificing comfort and convenience. Large 12 x 25 Footprint, Gorgeous Knotty Pine Interior, Full Bath, Kitchenette and Mini Split