corten steel extends former laundry complex’s brick buildings in kassel

Wäschereiquartier: Adaptive Reuse of Historic Kassel Laundry Site

The Wäschereiquartier in Kassel, Germany, is a mixed-use residential development created through the adaptive reuse and extension of a former laundry complex. Designed by Querkopf Architekten, the project transforms a previously sealed industrial site into a climate-conscious urban quarter and was awarded the Heinze Award 2025 in the category ‘Neighborhood and Mixed-Use.’

Located in the Vorderer Westen district, an area characterized by Art Nouveau housing and historic villas, the site consists of three listed brick factory buildings originally constructed around 1900 for the Welscher laundry. Situated within a rear courtyard of a perimeter block near Bebelplatz, the ensemble had undergone several unsystematic extensions over time. Querkopf Architekten, acting as both developer and architect, pursued a strategy of preservation, selective demolition, and careful densification. Single-story annexes and workshop sheds were removed to clarify the original building structure and reduce sealed surfaces. This intervention opened approximately 1,400 sqm of new green courtyard space and introduced a new access route from Dörnbergstrasse. In total, around 1,100 sqm of impervious ground were removed. Without expanding the site footprint, the gross floor area was increased from 2,200 sqm to approximately 6,000 sqm.

all images by Frank Löschke

Querkopf restores brick facades and adds corten steel cladding

The main building, known as the ‘Riegel,’ forms the center of the ensemble. Its brick facades were partially reconstructed, with approximately 40 percent rebuilt using 15,000 newly manufactured bricks that were mixed and integrated into the existing masonry. The facade composition is defined by pilaster strips, cornice bands, and steel-framed windows set deep within segmental and round-arched openings. The building was extended vertically by one and a half stories, with the addition clearly differentiated through a corten steel cladding. The new volume follows the proportions of the historic structure while remaining legible as a contemporary layer. Interior spaces range from compact apartments to larger loft units, shaped by ceiling heights of up to five meters and tall vertical window openings that bring daylight deep into the floor plans. Ground-floor apartments open onto private gardens, while upper levels include balconies and roof terraces, some oriented toward the preserved historic chimney.

Adjoining the Riegel at its northwestern end is the former production hall, which mediates between the main building and the angled geometry of the neighboring development. The hall features a white brushed render facade with contrasting window surrounds and large workshop-style windows. Energy upgrades were carried out on both the walls and roof, and the existing timber roof structure was refurbished. Roof windows set into the shallow gable roof introduce additional daylight. A restored steel pergola, echoing the hall’s pitched roof, defines the adjacent outdoor space. Parallel to the main building stands a single-story brick structure known as the ‘Punkthaus.’ Previously used for storage and later as a music studio, the building now contains two residential units. Original roof structures with exposed rafters and beams remain visible, paired with industrial steel doors, whitewashed walls, and contemporary bathroom fittings. A new six-story residential building on Dörnbergstrasse completes the perimeter block for the first time and establishes a clear street-facing address. The compact volume is clad in a ventilated corten steel facade that wraps continuously over walls and roof. The elevation is structured by a vertical panel grid, horizontal steel profiles, and narrow-format full-height windows. Balconies and flush dormers articulate the facade rhythm. The building contains 15 apartments and an underground garage with 16 parking spaces, including charging infrastructure for electric vehicles.

the exposed and landscaped inner courtyard of the neighbourhood

Querkopf integrates Climate-Responsive Design Strategies

Sustainability strategies were integrated across the site. The compact building volumes contribute to efficient energy performance, supported by district heating and compliance with the KfW Efficiency House 55 standard. Green roofs improve thermal performance and provide seasonal insulation. At ground level, gardens, fruit trees, wildflower meadows, and shared green spaces support biodiversity and rainwater infiltration. Additional amenities include bicycle and stroller storage, barrier-free access throughout the quarter, and clearly organized outdoor areas that support everyday use.

two structures as typological contemporaries; similar cubature, industrial character, patina

around 40% of the brick facades were reconstructed, with 15,000 new bricks tumbled, mixed and fitted

pilaster strips and cornices divide the facade

the side wings and central section of the building were raised by one story and extended with additional structures

the curtain-type, rear-ventilated corten steel skin extends homogeneously across the facade and roof

the former production hall adjoins the north-western front of the block

the six-story new building on Dörnbergstraße completes the perimeter block development for the first time

exposed concrete emphasizes the industrial character of the new building’s interior

the music band Milky Chance once rehearsed in the former storage area of the laundry

the exposed roof structure with rafters over 120 years old meets modern interiors in the two flats

project info:

name: Wäschereiquartier

architects: Querkopf Architekten | @querkopfarchitekten

location: Kassel, Germany

lead designers: Simon Mögel, Fionn Mögel

project manager: Fionn Mögel

design team: Frank Zander, Marcel Beyer, Aurélien Houille

GFA (before): 2,200 sqm

GFA (after): 6,000 sqm

site area: 3,300 sqm

sealed surface (before): 3,000 sqm

sealed surface (after): 1,900 sqm

green space: 1,400 sqm

number of apartments, main building (‘Riegel’): 12

number of apartments, production hall: 1

number of apartments, ‘Punkthaus’: 2

number of apartments, new building: 15

client/developer: Querkopf Invest GmbH – Fionn Mögel

structural engineer: Reitz und Pristl Ingenieur GmbH

landscape design: Querkopf Architekten

structural works/interior fit-out/landscaping: Fuchsbau Generalbau GmbH

facade construction: Metalbau Burckhardt GmbH

photographer: Frank Löschke | @frank_loeschke_photographer

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edited by: christina vergopoulou | designboom