Architecture begins with understanding what is already there.

Since 1998, D:4 has worked where architecture, preservation, and social design intersect. Founded by Marcus Nitschke and Jörn Focken, the practice has grown into an interdisciplinary team based in Berlin, Hamburg, Krems and Tirana, working across architecture, heritage conservation, strategic consulting, and cultural initiatives.

Our projects usually begin with the community. A building, a forgotten place, a complex portfolio, or a cultural landscape; a community whose next chapter has yet to be written. Rather than replacing what exists, we seek to understand it, then reveal new its possibilities while preserving the qualities that make each place unique.

Our work is guided by the conviction that sustainability begins with continuity. Building responsibly means recognizing the cultural, material, and social value already embedded in the built environment. Innovation, therefore, is not measured by novelty alone, but by the ability to connect past and future in meaningful ways.

We restore monuments, transform existing structures, design contemporary architecture, develop long-term strategies for large property portfolios, and advise public institutions, municipalities, and private clients. Every project is approached as part of a longer story, rather than an isolated object, whether working on a listed church, a kindergarten, a natural swimming pool, or an urban masterplan.

This perspective extends beyond construction. Through exhibitions, publications, research, and cultural collaborations, we explore architecture as a public conversation that shapes collective memory as much as physical space.

Constructions are never isolated artefacts; they are part of broader cultural, social, and ecological systems.

At D:4, architecture is ultimately an act of understanding: reading what time has been written, understanding what the present requires, and creating places that will continue to matter for generations to come, serving the community and the ever-changing society.