Modular cross-laminated timber construction: design and analysis of a lightweight system for educational

Abstract

Abstract: The urgent need to expand educational facilities rapidly and sustainably, while minimising disruption to their daily operation, has exposed the limitations of conventional construction systems based on reinforced concrete. At the same time, recent natural disasters in Spain, such as the La Palma volcanic eruption and recurrent severe storm events, have revealed the lack of dignified, efficient and technically robust solutions for rapid housing provision. These two apparently distinct challenges share common technical requirements: speed of execution, lightweight construction, high environmental performance, industrialised production and adequate levels of comfort, safety and durability. In this context, mass timber construction—and specifically Cross-Laminated Timber (CLT)—emerges as a strategic alternative capable of addressing both educational building extensions and rapid post-disaster housing. CLT is a highperformance engineered wood product that combines low self-weight, high structural stiffness and excellent prefabrication potential. Its plate-based structural behaviour allows walls and floors to act as load-bearing diaphragms, enabling mid-rise construction and vertical extensions on existing buildings without the need for structural reinforcement. This project develops a three-dimensional modular construction system based on CLT panels combined with a carefully designed multilayer building envelope. The proposed system addresses the main technical challenges associated with timber construction, including moisture sensitivity, interstitial condensation, acoustic performance and fire safety. Hygrothermal control is achieved through an optimised arrangement of insulation, vapour control layers and ventilated cavities, while acoustic and fire performance are ensured by multilayer solutions that comply with current regulatory requirements. The modular CLT system is conceived as a flexible and transferable solution. The same structural and envelope configuration can be used either as an educational classroom module or as a rapid housing unit, with only minor adaptations to the internal layout and services. This dual-use capability enhances the system’s value for public administrations, allowing it to be deployed efficiently in both planned educational interventions and emergency scenarios. Comparative analyses with reinforced concrete and metallic modular systems demonstrate that CLT offers significant advantages in terms of construction speed, self-weight, environmental impact and interior comfort. The study concludes that industrialised modular construction using CLT constitutes a technically viable, sustainable and socially responsible solution for contemporary educational infrastructure expansion and resilient housing provision in Spain.