Abstract: Disclosed herein is a door for traditional Korean houses. The door includes a structure of a lattice door framed with vertical lattice frames and horizontal lattice frames which are arranged in a regular periodic pattern. A lattice width-to-height ratio (W/H) of the lattice door ranges from 0.07 to 0.1 so that the outside air is prevented from entering the interior of a room through the lattice door to minimize heat loss from the interior of the room to the outside air. Therefore, the present invention can satisfy the basic function of insulating the interior of the room born the outside air. Thereby, energy consumption can be reduced.