Heritage Project 2025:
Mühlhausen

Traditional clay techniques at a
Building from the Middle Ages

CONS/RENO

14.09. - 25.09.

OH-H10
REQUIREMENTS: CV, Motivation Letter and interview
ACCOMMODATION: basic facilities, shared rooms with
beds, warm showers and toilets.
LOCATION: Mühlhausen, Thuringia

AGE: at least 20
LANGUAGE: very good level of English, other languages
are helpful

Mühlhausen, located in Thuringia, is a
town renowned for its well-preserved
medieval architecture and its role in
major historical events. Once one of
the most powerful Free Imperial Cities
of the Holy Roman Empire, Mühlhausen
flourished as a thriving commercial
and religious centre during the Middle
Ages. In the Mühlhausen suburb of St.
Petri, a historically important quarter
beyond the medieval city walls, a group of remarkably original half-timbered buildings has been
preserved in a prominent corner location. This area was historically home to artisans and labourers
linked to stone and mortar trades, such as lime burners, stonemasons, and tile makers, who played
a crucial role in the town’s construction economy. The ensemble at Zinkengasse 36 consists of four
single-room houses, each constructed at different periods, situated on three contiguous plots now
forming a protected historical courtyard. The corner house, identified through
dendrochronological analysis as dating back to the 1350s, is the oldest structure in the group, with
over 600 years of continuous history. This building retains early carpentry techniques, including
sword tenon joints and a continuous rail beam, methods no longer in use in later timber
construction. This collection of buildings is being developed as a heritage documentation and
research site, offering a unique perspective on urban working-class life in the 17th century. The
ensemble will be transformed into a museum-like setting, providing insight into the living
conditions of ordinary townspeople while preserving the architectural authenticity of the structures.
Training Course description
The heritage conservation project will engage the participants with the restoration of medieval
vernacular architecture, focusing on the historically accurate use of traditional materials and
techniques. The site, comprising a rare ensemble of medieval half-timbered buildings, is in the
early stages of its conservation journey, with ongoing structural consolidation and restoration
efforts. A central aspect of the conservation work will be the preparation and application of clay
mortar, a historically appropriate material used for wall rendering, stone setting, and floor
construction in buildings of this period. Unlike later structures that employed lime mortar, the
buildings at Zinkengasse 36 originally relied on clay-based mortars, and their conservation
requires a precise understanding of their material properties, application methods, and long-term
behaviour. The participants will engage in mixing and applying clay mortar, acquiring hands-on
experience in a technique essential to pre-modern construction. In addition to the work with clay,
conservation efforts will include the extraction and recovery of historic building materials, such as
natural stone and timber, which is planned to be carefully processed and reintegrated into the
structure. This process will involve traditional masonry and carpentry techniques, ensuring that the
restoration respects the original construction principles. The conservation tasks will be supervised
by a master stonemason specialising in dry-stone wall construction and traditional masonry
techniques.

EXTRA FEE: 150 euros