To expedite realization of magnetic fusion energy with the tokamak concept, a parallel process of developing engineering technologies required to design, fabricate, construct, start up, and operate the fusion DEMO plant of Korea (K-DEMO Plant) at the same time with researching fusion science and technologies in KSTAR (Korean Superconductor Tokamak Advanced Research) and ITER (International Thermonuclear Experimental Reactor) was adopted in the fusion DEMO program of Korea (K-DEMO Program). As a part of these engineering studies, an exploratory study on the layout and building schematics of K-DEMO Plant have carried out in consideration of economic and safety aspects. The buildings of K-DEMO Plant are named and their volumes are estimated with an order of magnitude analysis based on the sizes of the buildings of ITER and nuclear power plants. This exploratory study on the layout and building schematics is also required to estimate the costs of K-DEMO Program and analyze its economic feasibility.