Before founding GEMMA ZT GmbH, Ana, Simon, and Stephan realized award-winning projects at interior design studios and architecture offices in Vienna, Berlin, and New York City over the course of more than a decade. Their combined expertise in refined architecture and award-winning interior design informs GEMMA’s work every day, driving high standards for design quality, clear communication, and tangible results.

GEMMA creates future-proof architecture and interiors that people feel, remember—and return to. Guided by a holistic vision and a tailored approach, the work balances the energy of urban environments with the serenity of rural settings, always rooted in an optimistic, forward-looking mindset. At GEMMA, we believe that every space, grand or modest, can be transformed into a lasting, meaningful experience through thoughtful design.

Simon Aglas is a member of the Berlin Chamber of Architects as well as a state-authorised and sworn member of the Chamber for Chartered Engineering Consultants in Vienna, Lower Austria and Burgenland.

Before founding GEMMA, he worked as a Senior Architect and Project Manager at Zeitgeist Group in Berlin,  where he led the design and delivery of high-end projects across Germany and Switzerland, ensuring exceptional attention to detail and technical precision. Prior to this, he worked at the Berlin-based architectural practice LAVA as part of the core team on a visionary urban masterplan project in Saudi Arabia. He began his professional career at the Vienna-based architecture and design studio LABVERT, where he was responsible for a diverse range of projects across different scales and phases of development.

His architectural approach was profoundly shaped by his studies in Zaha Hadid’s Masterclass at the University of Applied Arts Vienna and  his skills were further honed at 
SCI-Arc in Los Angeles.

Before founding GEMMA, Ana Ritzer worked at leading architecture firms in New York City, realising complex, high-profile projects. She played a key role in transforming a former industrial peninsula on the East River in Astoria into a vibrant neighborhood with two residential high-rises, public spaces, and waterfront access. In Atlanta, Georgia, she managed two major projects from concept to completion:
a boutique mass timber office building and a high-rise with modular apartments including the interior design of amenity spaces. Ana led the design of a pioneering residential mass timber high-rise building – set to be the first of its kind in Washington, D.C. In Austria, she completed several residential projects in Vienna and Tyrol and contributed to exhibitions at the Architekturzentrum Innsbruck and the ZOOM Children’s Museum Vienna.

Her expertise spans in-depth technical knowledge and BIM proficiency, complemented by a refined sense of composition, materiality, and spatial experience. Ana studied architecture at Vienna University of Technology and the University of Applied Arts Vienna.

Before founding GEMMA, Stephan delivered a wide range 
of award-winning projects across multiple scales as a Director at a globally renowned design studio in New York City.  This experience shaped his belief that projects should be conceived as complete experiences, not merely as buildings.
His portfolio spans masterplans, five-star resorts for leading luxury brands, celebrity chef–driven restaurants,
and prominent residential and office towers in New York 
and Miami. He thrives under real-world pressure and excels at  advancing complex projects. In his work, he combines deep expertise in hospitality and experience design with a forward-thinking architectural sensibility, shaped by his studies in the Masterclass of Zaha Hadid in Vienna and 
at SCI-Arc in Los Angeles. 

His Tyrolean upbringing adds an approachable, human dimension to his international design vision, infusing meticulous craftsmanship into every project. The resulting spaces and objects are warm and inviting as much as refined and multi-layered.