The attic, an intermediate space between the ceiling and the roof with a middle-layered structure, necessitatesadditional research on subsidiary buildings due to the prevailing focus on main buildings and annex buildings in previousstudies. Recognizing this gap, the current study was conducted, with a particular emphasis on attics actively used in Andong,Gyeongsangbuk-do. The research targeted upper-class residences, specifically those designated as national cultural heritagewith well-preserved circular structures. Through the collection of literary materials and on-site surveys involving measurementsand photography, first-hand data was gathered and organized to form primary data. Survey results indicated that attics weremost commonly used in the order of main buildings, subsidiary buildings, and annex buildings. In subsidiary buildings, atticswere primarily located above stables, serving the purpose of storing utensils and preserving food during events. The flooring ofattics varied across structures, primarily consisting of earthen finishes. Wall structures universally employed mud walls,maintaining consistency by incorporating wall finishes used in the main structures. Window frames used in attics werepredominantly of the "man-sal-chang" type, with double-lattice windows being the most prevalent. This choice was likely madeto meet both functional demands and aesthetic considerations. The access to attics was primarily achieved through the use ofsupports, especially in bedrooms and kitchen attics, providing a method that allows access without encroaching on surroundingspaces in narrow environments. Although this research focused on upper-class residences in the Andong region, thesignificance lies in addressing the less-explored attics in subsidiary buildings. The primary data collected serves as a valuablereference and comparative material for future reconstructions and restorations of Andong region houses.