Abstract: An arch structure for an earth sheltered building includes a plurality of curved wood panel sections arranged in tandem and in a plurality of adjacent rows. The sections are joined adhesively and define an arch resting on a foundation of footings. Each of the panel sections includes side members joined to end members and ribs extending between the side members and between the end members. Joined to the members are top and bottom skins which enclose the panel and in conjunction with the ribs define a plurality of compartments. Insulation material is disposed within the compartments. At least one of the skins is offset on the side members to define male and female portions which are joined with panel sections in adjacent rows. The panels are fabricated from wood. After assembling into the arch form, the panels are covered with an exterior sheathing which is pressure treated and waterproofed. End walls are attached to the arch section, and the structure is covered with earth.