The chapel was built in the 15th century, replacing a chapel from 1422 that belonged to a
Pestspital, a hospital for patients with the
plague. That building was badly damaged during the invasion by Turks in 1480. Four wealthy citizens including the Kornmesser, Pögl and Holzapfel families financed a new building. It was erected from 1495 to 1497 as a monument of thanks for the survival of plague, hunger and war. The donors were merchants who contributed to the flourishing of Bruck, located where important roads of the day met. Further donors whose names are mentioned in wall decoration belong to a younger generation. One inscription, dated 1504, mentions
figura aura, the golden ratio which governs the proportions of the building. Protocols dated from the 1540s confirm that the building was used for church services as a filial church of Bruck. 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. Services were held in the chapel until 1783. When no longer used, the building fell into disrepair. In 1794, the Catholic Church conducted a ceremony of
deconsecration of the chapel. It was then used by the postmaster Ignaz Weigel as a stable and hay storage for the carriage horses. In 1817, Franz Oberländer received permission to remodel the building as a guest house, called Geistwirt. Further restructuring happened in 1921, destroying the Gothic windows. The town of Bruck acquired the building in 1955 and used it as housing for its personnel. For this purpose the interior was divided, with two upper floors with several rooms each. When a nearby highway was expanded there were plans to demolish the chapel. It was prevented, but living so close to major traffic became unbearable, and the building remained empty from 1999. The building was recognised as unusual in the 19th century, by publication of the floor plan and images of the vault. Johann Graus requested restoration in 1882. Two doctoral theses focused on the building, in 1999 and 2000. Related to these works, the art historian Mario Schwarz pointed out the sad state of this unique Gothic monument.
Philipp Harnoncourt, who was interested in the arts focused on the Trinity, decided in 2011 to work towards the restoration. He first convinced his six siblings including
Nikolaus Harnoncourt and
Franz Harnoncourt, and then the government of Bruck, to support the plan to restore the building, to serve as a monument for the protection of the environment. On June 7, 2020,
Trinity Sunday, as Philipp Harnoncourt had wished, the completion of the restoration of the Holy Spirit Chapel in Bruck an der Mur was celebrated with a ceremony - just a few days after his death and one day after his funeral in Grundlsee. The celebration during the COVID-19 pandemic was presented per
livestream by the town of Bruck. == Architecture and restoration ==