Church:
The chancel was usually built first;  at Dale, probably the rest of the church was built between a first chancel  and this one we now have. The abbey was probably wholly rebuilt 50 years after foundation (WARD).
Early English (H80).
East window tracery c. 1250-60.

Nave 13th century.  Clerestory windows of the nave are Perpendicular (H83), around 1440 (WARD).

The foundations of the arcade between the chancel and St Margaret's chapel:  the bases are also Norman.  The 13th century arcade was out of gear with these, so the rebuilders built a respond on the east side of the great pier thus making the pillar 'move' as far to the east as possible. Even so the westernmost arch is smaller than the others.  

Lower walls of Lady Chapel 13th century (WARD).   
The lower walls of chapel (does he mean the Lady Chapel?) are 13th century (H80, WARD).

St Werburgh's chapel was rebuilt in the early 14th century (C41).
St Werburgh's chapel has 14th century pillar bases, but the eastern respond of arcade is much earlier. Was the chapel partly rebuilt in the 14th century?  (WARD).

The pillar bases between St Margaret's and St Werburgh's chapels are Decorated (H79).

St Margaret's chapel was built c. 1333, (HOPE).  Its east window was a bit later than the chancel east window.

The north east pier of crossing has an earlier plinth and the14th century north and west responds of the south east pier rest against an earlier, square pier (Norman or Transitional). Are the north east pier and spiral stairs 13th century?

Dating (of parts of the abbey)