It was built in late-Gothic style, originally dedicated to the Trinity, which explains its unusual triangular floorplan, with three similar walls, all with a portal.

The building fell into disrepair in the 18th century and was used for several purposes such as a postmaster's stable, an inn and for housing, which changed the interior.

In a protocol of 1617, Bishop Jakob Eberlein noted the triangular floor as unusual and demanded that the altars be returned to the apses, to concur with the intentions of the first builders, and to ease listening to masses from outside.

Related to these works, the art historian Mario Schwarz pointed out the sad state of this unique Gothic monument.

Inside, the corners house three equal apses, making it an equilateral hexagon floor,[7] which is crowned by a three-fold star rib vault.

[7] The restoration of the original appearance was possible, because exterior and interior features were preserved, at least on one side, and could be reconstructed knowing of the symmetry.

[7] Surviving interior decoration was rediscovered in 2013, included red chalk graphics with remains of the Stiftungsinschrift (foundation inscription) of 1497, which names Bruck citizens and shows their coats of arms: Pankraz Kornmess, Michael Holzapfel, Leonhard Schierling and Albrecht Dyem.

For missing elements, such as a floor, the windows and lighting, an architecture competition was held to include contemporary art.