I propose a reconstructed model of the main sanctuary at Izumo-Taisha Shrine in the Keicho period. It was 5 ken (35 shaku, approximately 10.605 meters) wide, 5 ken deep, a ken was equivalent to 7 shaku, and 6 jo 5 shaku 4 sun (approximately 19.816 meters) high. I presume that it didn't have a pillar that supports the ridge beam directly (manamoti-bashira), and it had a roof construction system based on one slightly curved beam (koryo) and principal rafter with king-strut (inoko-sasu).