Complex sentence: Construction took seven years, and was sufficiently far along that consecration was planned for St. Peter and Paul Day of 1761 when-two days beforehand, on 27 June 1761-the entire village of 60 houses burned down, including the church.
Split into simpler sentences: Construction took seven years, and was sufficiently far along that consecration was being planned for St. Peter and Paul Day of 1761. Two days before this, however, on 27 June 1761, the entire village of 60 houses burned down, including the church.