A warehouse was converted into a residential space for a young couple who like bouldering which is a kind of free climbing and a sport to climb rocks of two to four meters high without lifeline. The inside walls are designed in several leaned parts for them to attach some instruments to practice bouldering. For changing the nature of the building we came up with additional walls minimizing the modification to the existing building. As the outside walls were of ACL and the resistance against heat and rain were anticipated, they are covered with corrugated galvalume steal plates with heat insulator attached on the back. Floor heating with heat condensing stuff is laid over the existing floor for maintaining air conditioning of the big volume space. We can use electricity cheaply during a period at night. The air conditioning system uses such electricity to heat the floor concrete with heaters buried therein. Sunlight through the fixed large window will additionally heat up the floor. Electric energy and sunlight stored in the floor concrete will be released from the surface throughout the day.The existed shutter was removed and a big window is provided instead. Taking advantage of parking space in the front, the fence was furnished with corrugated plates of light transmitting milk-white for the eyes from the street to be taken off.The design was made to be converted into a light, broad residential space for the young client who likes carpentry as well.