The first post-Romanesque addition to the cathedral was the western rood screen.
This was done in the Gothic style at the time of the western renovations.
Following this example, the intersect area was heavily renovated in the next few centuries in the Gothic style.

Starting in 1279, Gothic chapels featuring large decorative windows were built onto the cathedral.
In 1418 the Nassauer Chapel, a freestanding burial chapel in the middle nave was built at the request of Archbishop John II of Nassau.
The construction of this chapel is attributed to Madern Gerthener, who was also responsible for the Memorial Chapel built into the entrance hall to the western wing of the intersect area.

The towers were also renovated during this period.
Belfries were added to the two towers at the crossings, on the eastern tower in 1361 and on the western in 1418.
These towers were topped with Gothic-style pyramid roofs. (
These towers turned out to be so heavy that the eastern tower had to be supported by a pillar erected in 1430.)

The cloister was heavily renovated and the Liebfrauenkirche was completely replaced at this time, marking the last of the Gothic renovations to the building.
The roof on the eastern tower, however, was replaced in 1579 by a flatter one due to weight concerns.
After that, no major alterations were made to the cathedral for almost two centuries.
The first post-Romanesque addition to the cathedral was the western rood screen. This was done in the Gothic style at the time of the western renovations. Following this example, the intersect area was heavily renovated in the next few centuries in the Gothic style.
Starting in 1279, Gothic chapels featuring large decorative windows were built onto the cathedral. In 1418 the Nassauer Chapel, a freestanding burial chapel in the middle nave was built at the request of Archbishop John II of Nassau. The construction of this chapel is attributed to Madern Gerthener, who was also responsible for the Memorial Chapel built into the entrance hall to the western wing of the intersect area.
The towers were also renovated during this period. Belfries were added to the two towers at the crossings, on the eastern tower in 1361 and on the western in 1418. These towers were topped with Gothic-style pyramid roofs. (These towers turned out to be so heavy that the eastern tower had to be supported by a pillar erected in 1430.)
The cloister was heavily renovated and the Liebfrauenkirche was completely replaced at this time, marking the last of the Gothic renovations to the building. The roof on the eastern tower, however, was replaced in 1579 by a flatter one due to weight concerns. After that, no major alterations were made to the cathedral for almost two centuries.
Mainz Cathedral