In the ongoing discourse on the recyclability and sustainability of building materials, this study explores the potential of paper-based materials for use in construction, with a particular focus on their hygrothermal performance. Current research suggests that paper, with its well-established recycling cycles, is a promising and cost-effective alternative to conventional building envelope materials, such as lightweight timber or steel frame constructions. The primary objective of this work is to provide fundamental insights into the hygrothermal behaviour of a building envelope constructed from paper-based materials, in particular corrugated board and cardboard, under real climatic conditions. To achieve this goal, a prototype paper-based building envelope was constructed, and its building physical performance was metrologically recorded through extensive temperature and humidity measurements over a winter period. These field measurements were complemented by numerical simulations. The comprehensive evaluation of both the empirical data and the simulation results highlights the potential of paper-based materials as a sustainable building option in the construction industry. Particularly noteworthy is their commendable thermal performance, suggesting a promising role for paper-based materials in improving the overall environmental profile of buildings. This study contributes valuable insights to the ongoing discourse on sustainable building materials and advocates the integration of paper-based solutions into building practice.