The belfry with its gable roof, rebuilt in gothic style in 1220, is now the only surviving part of the original Roman church. As the nave of the earlier church was delapidated and had become too small, it was demolisched in 1807 and replaced by the present vast nave, built in the "barn" style in 1808 and 1809.
https://www.tourisme-alsace.com/en/253000970-Church-Saints-Peter-and-Paul.html