To apply the subject structure easy in management and installation also to floor heating on a higher floor of a multistoried building.

In a structure of accumulating heat through a building body for supplying heat to warm a floor surface, reinforcements 27 and 28 for one layer along of concrete slab mainly forming a floor part containing the floor surface are arranged in a mesh over the entire surface nearer one third from the side of the bottom surface of the concrete slab 14 while hot water circulation pipes 12, 12... are arranged along the reinforcement 28.