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ÖFFENTLICHE BAUTEN • PUBLIC BUILDINGS TECHNISCHER AUSBAU • TECHNICAL SOLUTIONS

Direkter Vorher-nachher-Vergleich (oben vor Umbau) der behutsamen Erneuerung und Erweiterung der Schule in Ziegel und Sichtbeton • Before-and-after comparison (above: before conversion) of the careful renovation and extension

Neue Außentreppen ergänzen das Brandschutzkonzept und das Erschließungssystem. • New external staircases complement fire protection concept and access system.

T he main challenges in dealing with the existing buildings stemmed from changes 20 years, the buildings are still in excellent condition; the robust, high-quality materials
in fire safety regulations and the need to expand the cafeteria’s capacity from 80 to
have stood the test of time and have been free of unpleasant emissions.
400 meals. The highest priority was maintaining the original typology and the defining
spatial concept of the generous, open internal ‘street’. “We actually didn’t want to change Fire safety as a driving force
anything at all, because we really like the school with its remarkable craftsmanship.”
To quintuple the kitchen capacity for full-day operations, the small kitchen had to be The outdated fire safety concept could no longer be retained. The elongated building part
dismantled and expanded. The former caretaker’s apartment had to make way to accom- 1 had to be divided into two smoke zones. Discreet glazing with smoke protection doors
modate the increased space requirements of the building services and another emergency provides separation while preserving the open character of the corridor hall. Five addi-
staircase. The dining hall was enlarged from 100 to 160 seats and extended at both ends tional emergency staircases were added for compensation – four of them external. These
with a storage room and a space for ventilation equipment. Supply and exhaust air ducts improve accessibility of the upper floors for the fire brigade and, together with 1.20-metre-
are hidden behind an acoustically effective slatted ceiling, identical in construction to the wide bypass doors, provide independent second escape routes directly to the outside. The
original. This new ventilation system is also used for night cooling; it supplies fresh air new doors also make it easier to supervise adjacent classrooms simultaneously. The two
during the cooler nighttime hours. The night cooling is now automated and optimised in concrete stair towers in the schoolyard stand at a clear distance from the existing building.
both building parts, mainly through additional ventilation flaps that allow cooler night air A roof structure spans between them, serving as a shelter and sunshade during breaks
to enter from below and warm air to escape along the strip of skylights. Another low-tech and, together with the connecting walkways, define the outdoor are a in front of the cafe-
measure is the optimsed solar protection: the original red awnings were replaced with a teria. The street-side steel staircase and the concrete stairs on the north side leading to the
new, light-coloured screen fabric with higher reflectance and lower transmittance. Contrary garden in front of building part 2 hardly touch the existing structure either. They blend in
to the spirit of the time, the school was built with relatively little technical equipment. so naturally that they appear to have been part of the original design. The dining hall was
Mechanical ventilation exists only where absolutely necessary. Ventilation is generally fitted with glazed T30 smoke protection doors with hold-open devices along the corridor,
done via the windows. The masonry portion of the façade is relatively high, demonstrating preserving the open spatial continuity of the cafeteria while allowing it to be used flexibly
the advantages of a double-leaf brick façade over a glass façade: significantly lower costs, and independently of regular school operations. The classroom doors were upgraded and
higher thermal mass, better insulation values and longer durability. Even after more than are now self-closing and smoke-tight. The comprehensive installation of smoke detec-

116 • AIT 5.2025