Converted log structural products are produced from conventionally unusable or marginally useful sections of logs transversely cut into suitable lengths and then cut longitudinally by perpendicular cuts into log parts of either right-angled sector or right triangle cross-section. Four log parts matching in size and shape, and positioned so that their right angles form the corners of a rectangle, are assembled into a converted log, the interior space between the four log parts being filled selectively with braces, supports, insulation, concrete for various applications.