The oldest building on the site of the current church in Oliwa was commissioned by the founder and his descendants in the 1280s (Oliwa I) and at the beginning of the 13th century (Oliwa II). The first building, Oliwa I, consisted of a small oratory with a groin vault, an apse facing east and a turret with a staircase from the south-west. In the new plan of Oliwa II, the oratory became a chancel, raised to the level of the frieze under the eaves in the transept. The next phase of construction, dating from 1230 to 1250, saw the reconstruction of the abbey in the Bernardine style. The transept was flanked from the east by two chapels, and in the northern arm a chapel was also added on the west side. The entire building was divided into three bays, and the facade was completed with a polygonal turret in the southwest corner of the nave. Architectural details indicate the influence of two different styles: Danish and northern German. In the 1370s and 1380s, the architectural plan of the eastern part of the church was completely changed. The apse of the presbytery was demolished and enlarged with an additional pillar. The twin eastern chapels were replaced with two naves, creating an integrated, three-nave hall. The new chancel was connected to the side aisles with four pointed arcades, and a smooth wall probably closed the corridor. This reconstruction puts Oliwa ahead of Koronowo as an example of this type of architectural design. After the fire in 1350, which destroyed the Oliwa Abbey, no major changes or alterations were made to the building.