The original building from the 1970s underwent an expansion with the addition of a courtyard building. This new structure seamlessly connects to the existing one, thanks to a strategically placed staircase core. What sets this timber construction project apart are its intricate details and the utilization of various timber components. These include the timber frame construction method, KLH® – CLT wall and ceiling elements, ribbed ceilings, and timber-concrete composite ceilings. The expansion of HLT Retz serves as a remarkable example of sustainable timber construction and contemporary architectural design.