A terraced house roof expansion in Aachen with Velux skylights was documented in the German Architects' Journal as an example of residential space extensions. The project responds to increasing demand for additional living space in existing buildings, as new construction land becomes scarcer and real estate prices rise. Roof story expansion in terraced houses is constructively feasible because load-bearing walls are usually run continuously up to the roof. The skylight integration enables compliance with minimum requirements for daylight and ventilation according to state building regulations for occupied rooms.