The purpose of the present invention is to construct a structure with the functions of a firewood boiler, a pavilion, and a Korean dry sauna, wherein the structure is applied with a returning (daedongorae) type among traditional hypocaust types, and is capable of supplying heating to even a distant place by converting heat in a hypocaust into hot water using a pipe to obtain the hot water, wherein the returning (daedongorae) type to prevent the heat from being lost through a stovepipe is capable of reducing heat loss which is the weakness of an existing firewood boiler, and the pipe buried on the hypocaust is not a copper pipe, but an XL pipe inexpensive and easily worked. For the above effects, the XL pipe is buried after covered with pebbles at a thickness of 7 cm after spread with loess at a thickness of 2 cm so that damage to the XL pipe on the hypocaust can be prevented, and a fire door having refractory bricks is used and a fire door adjusting unit separated from the fire door is positioned below the fire door so that the heat in the hypocaust can remain for a long time. In addition, a pavilion structure at the upper side of the hypocaust is basically and completely insulated, in particular, has: an entrance with an insulating double-window and three of the double-windows capable of being opened or closed. Therefore, the sealed pavilion structure can function as the Korean dry sauna in which waste such as sweat is excreted from the body of a user so that the metabolism of the body can be activated, and the opened pavilion structure receiving outdoor air can function as the pavilion.COPYRIGHT KIPO 2014본 발명의 목적은 화목보일러, 정자 , 찜질방의 기능을 함께 갖춘 구조물을 만들되 화목보일러의 단점인 연통으로 많은 열이 손실 되는 것을 막고자 전통구들방식 중 적은 평수에서 열손실을 적게 하는 되돈고래(대동고래) 방식을 이용하고, 온수를 얻기 위해 구들 위에 매설하는 파이프를 동 파이프가 아닌, 비용이 적게 들고 작업이 용이한 엑셀 파이프를 이용하여, 구들속의 열기를 온수로 변환시켜 거리상 먼 곳 까지도 난방 할 수 있다는 것이며, 이를 위해 엑셀파이프가 구들 속에서 손상 받지 않게 하기위해 황토 2cm 도포 후 자갈 7cm를 덮은 후 매설한다는 것과, 구들속의 열기를 오랫동안 머물게 하기위해 내화벽돌이 함유된 불문을 사용하고 또한 불문 조절구는
