Naturally sustainable materials that enhance indoor climate quality and a thoughtful reuse strategy for the existing structure guided this renovation project by Catalanoquiel Architects in Cologne's Lindenthal district. "More clay, please" became the defining principle. The two-story 1930s semi-detached house—already renovated once fifty years ago and extended with an underground pool—needed reimagining: the goal was spacious, open rooms designed for connection and enjoyment, matching the family of six's vision for a home that would simply feel "fun." The project also meant bringing the dormant pool back to life and creating additional living space below ground.

The renovation presented substantial challenges. Creating an open ground floor required merging multiple rooms, but the building's complex, tightly layered structure—including areas with dangerously thin ceilings—pushed back. The site itself was equally demanding: the property boundaries were built right up to the edge on one side, making the underground expansion logistically complex and crane-dependent. The architects' core commitment was to honor the existing structure, maximize material reuse, and weave the family's needs seamlessly into what was already there. Cement was eliminated wherever structurally feasible—replaced with eco-concrete that cuts CO₂ emissions by 40 percent while remaining recyclable. Nearly all interior drywall relied on clay building boards with biologically beneficial properties, finished with clay plaster and, in select spaces, a durable clay fine coat. Even the ground floor became a statement: an 8-centimeter floating rammed earth floor that grounds the space literally and conceptually.

Upstairs, where a screed already existed, the solution was simple: full-length solid oak flooring, with sustainable linoleum in secondary spaces. For climate control, the architects designed an equally thoughtful system powered entirely by renewable energy. The clay-plastered ceilings hide integrated radiant heating and cooling fed by a heat pump. A rooftop photovoltaic system generates electricity, while solar panels handle domestic hot water production. A wood-burning fireplace adds character and heat to the wall heating network. A sophisticated smart home system orchestrates everything seamlessly.

www.catalanoquiel.de

Photography:

Marie Kreibich
www.mariekreibich.com

(Featured in CUBE Frankfurt 02|25)