With its central location in Dortmund and proximity to transit options, the property at Rheinische Strasse is an ideal location for high density co-working space. The prominant site, within the creative radius surrounding the Dortmund U, offered a unique opportunity to create a forward-thinking, sustainable building that would become a catalyst for improving the regional building codes to allow for more extensive use of mass timber in large-scale commercial buildings. U-Work is arranged using a rigid grid of glue-lam columns supporting hybrid CLT slab elements that demonstrate the capabilities of engineered lumber without sacrificing any of the acoustic performance necessary in a co-working space. The scale of the neighboring buildings is reflected in the building volume, and the building binds itself further to the surrounding context, by providing a publically accessible ground floor with restaurants and cafes. Visitors and residents of the co-working space are drawn into a large concrete atrium, which creates a direct connection between the bustling street, and serene courtyard in the center of the site. The Atrium includes a broad wooden staircase that serves as a venue for social events or informal meetings and also links the ground floor to a vertical timber environment at the core of the new building. Group work areas and meeting spaces surround the timber structur, encouraging interaction and collaboration, and the skylights provide ample light to the deep building’s interior. At the perimeter of the co-working floors, hot desks are aligned with wide operable windows that allow for optimal working conditions. The repetitive structure is reflected in the rhythm of the exterior facade. A grid of generous, wide openings contrasts the typical vertical geometry of standardized German office facades, and represents a new zeitgeist in office design, where buildings must be more generous with light and air quality, and everyone must be more conscious of their environmental footprint. Along those lines, this design proposes less than half of the normal parking spaces allotted for a new office building. Additional bike parking, access to transit, and double-decker electric fleet car parking are all integrated to reduce the amount of excavation and prevent the over construction of car-centric infrastructure. The U-Work proposal reflects the demand that architects and developers be more conscious of the effects their buildings have on both the local and global environment. In this project, we tried to create positive work spaces for co-workers, a contextual building with an active, public street level, a development case that provides maximum density on an urban site, and a sustainable construction, which reduces the CO2 normally associated with new construction.