Buildings with unusual occupancies or high levels of complexity (e.g. some large mixed-use retail, conference centres, and hospitals)
adeiladau â meddiannaethau anarferol neu lefelau uchel o gymhlethdod, er enghraifft canolfannau siopa ble y ceir nifer uchel o siopwyr a gweithwyr, canolfannau cynadledda ac ysbytai