Church of St Anna – restoration of windows, Prague - Old Town, Czech Republic

Address:	Kostel sv. Anny, Anenské náměstí 211, Praha 1
Description of work:	Restoration of windows
Investor:	Dagmar and Václav Havel Foundation VIZE 97
Contractor:	GEMA ART GROUP a.s.
Implementation:	11/2006 – 08/2007

History

According to the chronicler Václav Hájek of Libočany, the history of the site dates back to 927 when Prince Wenceslas supposedly founded a church dedicated to St Vavrinec there. These assumptions were disproved in the 1950s after an archaeological survey led by Ivan Borkovský was carried out and the remains of the original building, presumed to be a Romanesque rotunda, were dated to the first half of the 12th century.
The construction of today’s Gothic single nave church with an enclosed polygonal chancel took place in the 14th century. In 1313 the church became the property of the female Dominican Order and the first phase of the building of the Church of St Anne probably dates back to this time. The new chancel was then built, but it is most likely that for several decades further work was abandoned. The church was completed in the 1460s, a date which is supported both by written sources and archaeological examinations. Fragments of votive frescoes from the 1470s are still preserved in the interior and they exhibit a stylistic connection to the monumental courtly painting style of the reign of King Charles IV. A new Dominican monastery adjacent to the church was built at the same time.
The whole complex was one of the few spared from plundering during the Hussite wars. This was attributed to the alleged kinship between the abbess and the Hussite leader Jan Žižka of Trocnov, rumoured to be the abbess’s nephew. The monastery continued to function until 1782, when it was abolished as part of the reforms instituted by the Emperor Josef II.
The complex was bought in 1795 by Jan Ferdinand Schönfeld, who established printing works in its premises. Schönfeld’s Prague paper was printed there till 1835, when the works were taken over by the Haas Company. Towards the end of the 19th century the buildings underwent partial adaptations: the original Gothic vaulting in the church was demolished, the church tower lowered and some tombs filled in. By that time the church itself became significantly dilapidated.
The Hass printing works located in the former monastery and the Church of St Anne have their place in the history of the newly established Czechoslovak Republic as the issuers of its first banknotes with the nominal value of one Crown, printed in 1919. The works continued in existence even after the end of World War II under the name “Svoboda” National Enterprise. Production ended here in the 1970s and the complex came under the administration of the National Theatre. Urgent repairs were carried there between 1984 and 1993.
The Dagmar and Václav Havel Foundation VIZE 97 rented the church in 1999 for the symbolic sum of 1 Crown. The salvage and reconstruction work of the interior under the guidance of the architect Eva Jiřičná commenced in 2002. GEMA ART GROUP a.s. became involved in the reconstruction of the monument in the years 2006 and 2007, when the restoration of the stained glass windows took place.

Restoration work

Restoration work undertaken between November 2006 and August 2007 concerned the renovation of the stained glass windows of the Church of St Anne. The blueprint for the renovation was drawn up back in 2006.
GEMA ART GROUP a.s. was the main contractor for the specialist restoration work. The project was divided into several phases, which included a summary of the restoration intent, measurement of the windows, removal of the stained glass, refitting of the metal parts and manufacture of new windows. GEMA ART GROUP a.s. was also responsible for the installation of appropriate scaffolding.

Restoration of the windows – survey of the window scuncheons:
Restoration work concerned in total 16 windows: 4 large, 6 medium and 6 small windows. Before the start of the work special probes were inserted into selected scuncheons. The evaluation of the probes established the presence of lime mortar, which was subsequently repeatedly covered with a lime wash. No fragments of older ornamentation were found on the surface of the scuncheons.
The parapets bore traces of hardened coatings. The stone blocks had become loose in places. Several windows had later additions of unsuitable wooden shutters; their removal was recommended by the experts. The remnants of an original metal frame and glazing in the second window of the west-facing wall were a valuable find.

Restoration of the windows – measurements:
As the existing unprofessional alterations to the windows were unsuitable – the replacement panes were made of Plexiglas, yellowed by sunlight – it was decided to manufacture copies from cathedral glass.
Exact measurements of the windows were required for this task. Because of the height of the windows and difficult access to them, the measurements were taken using a mobile tower.
Restoration of the windows – manufacture of the stained glass panels:
The panels are clear glass hexagons with a 2.5 centimetres red border. The cutting of the hexagons was executed after detailed calculations on a special device with a 60º cutting angle. The edges of the individual hexagons were afterwards manually abraded.

Restoration of the windows – insertion of the individual hexagons into lead beading, installation of the windows in the church:
After the manufacture of the individual hexagons from clear glass, the panes were inserted into lead beading and soldered with a solder containing 60% of pewter. Glazier’s putty was used as sealant, followed by polishing with wood sawdust.
The assembly of the stained glass for the lanceted windows was carried out using paper templates and the restored complete windows were then fitted in place in the church.
Restoration of the windows of the Church of St Anne included the manufacture and installation of special drainage channels for the run-off of condensation.