To promote underfloor ventilation efficiency and to constitute easily a footing packing at a low cost without using a conventional clamping member to promote a monolithic joint effectively between footing packing and strip footing.

Anchor bolt movable holes 26 with an opening width having optional installation flexibility for passing through an anchor bolt 23 are bored in the thin plate-like substrate 25. Thin circuit pedestals 27 are monolithically projected to the side horizontally installing a sill beam member 22 placed on the substrate 25 thereon in a state of monolithic arrangement excpt sites of the anchor bolt movable holes 26, and projection 28 having an acute sharp end angle capable of being cut are provided to the approximate centers on the upper surfaces of the pedestals 27 so that they are firmly interlocked with the lower surface of the sill beam member 22.