A first bryological study of 31 wooden houses situated in 16 historical villages of the Kizhi parish on 4 islands and on Zaonezhsky Peninsula was carried out in the Kizhi Open Air Museum and its buffer zone. We found that in the past, wooden houses in this area were more commonly heat-insulated using semiaquatic mosses rather than forest-mire moss-es (Polytrichum commune, species of the genus Sphagnum). Sixteen species were iden-tified. The main ‘building’ moss was Warnstorfia exannulata. The presence of Scorpidium scorpioides, Scorpidium cossonii, Calliergon megalophyllum, Drepanocladus aduncusis noticeable. Previously (before the construction of the Nizhne-Svirskaya hydropower plant in 1952), these mosses used to be collected from shallow bays of Lake Onega.