Search Results (32)

This article presents a multi-criteria comparative analysis of modern wall partitions in light-frame technology, with a focus on highly energy-efficient modular construction. The motivation for this research stems from the critical need to optimize building thermal insulation materials to minimize heat loss, while simultaneously ensuring low structural weight, rapid assembly, and hygrothermal safety in prefabricated systems. The aim of this study is to identify the most advantageous insulating materials and structural configurations by evaluating their thermal transmittance, moisture behavior, thermal dynamics, and fire resistance. The analysis encompassed four structural variants paired with seven types of advanced and conventional insulation materials. This comprehensive matrix allowed for the development of 28 computational models. Simulations were carried out for severe winter climatic conditions in Poland, utilizing the Ubakus software and conforming to the PN-EN ISO 13788, PN-EN ISO 6946, PN-EN 12524, and DIN 4108-3 standards. The simulations assumed strict steady-state boundary conditions for a 90-day condensation period, with an external profile of −14 °C/80% RH and an internal climate of 20 °C/50% RH. The evaluation focused on key physical and energy parameters, including the heat transfer coefficient (U-value), condensation risk, diffusion resistance, thermal phase shift, and partition weight. Quantitative findings reveal that the ventilated system with resol foam insulation (variant 4d) yielded the best overall performance, achieving a U-value of 0.089 W/(m²·K) W/(m²·K). The results confirm that the strategic selection of high-performance thermal insulation materials, coupled with structural thermal bridge mitigation, significantly enhances the energy efficiency, thermal stability, and moisture resistance of lightweight enclosures, establishing a comprehensive comparative framework for optimizing modular building envelopes. Full article

Housing industrialization and modularization have gained traction as responses to two pressing challenges in the construction sector: the chronic shortage of affordable housing and the substantial environmental footprint of conventional building methods. Yet prevailing modular housing models in Europe remain constrained by dependence on global supply chains, production concentrated in large industrial operators, and insufficient adaptation to local material and territorial conditions. This article presents a state-of-the-art review of modular timber housing in Europe, examining technological typologies, market structures, and national regulatory frameworks. The methodology integrates a systematic literature and market review, a comparative country analysis, and an embedded case study. Findings indicate that the viability of modular timber housing depends not only on material performance but on its embeddedness in coherent industrial systems, business strategies, and regulatory contexts. Against this backdrop, the VICHO project is introduced as a case study exploring an open, proximity-based industrialization model that valorizes local poplar timber in southern Europe, in alignment with circular bioeconomy principles and the New European Bauhaus. Full article

The UK faces an urgent challenge to simultaneously accelerate housing delivery and reduce whole-life carbon emissions, yet robust empirical evidence on the carbon performance of modular steel housing remains limited. This study aims to quantify the carbon impacts of a modular light-gauge steel frame social housing dwelling in the UK and to benchmark its performance against contemporary low-carbon construction typologies. A cradle-to-grave life cycle assessment was conducted using primary project data from a real modular housing development, with embodied carbon modelled in One Click LCA and operational energy assessed through SAP 10.2-verified datasets. The results indicate a total whole-life carbon footprint of 91.3 tCO₂e over a 50-year period, with embodied emissions (A1–A3) accounting for 38.2% and operational energy and water use contributing 48.1%. The normalised embodied carbon intensity of 366 kgCO₂e/m² (A1–A5) is comparable to recent high-performing cross-laminated timber buildings, demonstrating that optimised modular steel systems can allow for low-carbon outcomes typically associated with bio-based construction. Sensitivity analysis shows that low-carbon foundation concrete, bio-based insulation, and steel optimisation can reduce upfront emissions by approximately 8–10%. Dynamic energy simulations were also used to assess how different design choices influence operational carbon emissions. This study provides transparent, real-project evidence of the whole-life carbon performance of UK modular light-gauge steel frame housing and identifies practical design strategies for further decarbonisation. The findings support informed decision-making for policymakers, designers, and housing providers seeking scalable, low-carbon residential solutions. Full article

Despite timber’s strategic role in the circular economy, its application in Türkiye remains negligible compared to the rigid reinforced concrete (RC) housing stock, which limits flexibility and penalizes the environment. This study investigates the adaptability and environmental performance of modular timber construction via a 17-year longitudinal case study in Seferihisar, İzmir. Using architectural observation, user interviews, 3D BIM, and a comparative LCA, findings reveal the structure successfully accommodated a six-phase functional transformation—the structure’s gross floor area increased by 6.19 times more (from 21 m² to 151 m²) and bed capacity from 2 to 18—with virtually zero demolition waste through dry-assembly techniques. Crucially, normalized LCA proves timber’s ecological superiority: achieving an embodied energy intensity of 6.60 GJ/m² (1.2 times less than the RC equivalent’s 7.97 GJ/m²). Furthermore, biogenic carbon storage enabled the timber dwelling to reach a negative Global Warming Potential (GWP) of −26,118.39 kgCO₂ (a carbon sink), whereas the RC model emitted +39,081.22 kgCO₂. Given that secondary housing predominantly comprises two-story structures, lightweight timber sustainably meets this typological demand. Ultimately, user-driven modular timber presents a resilient, eco-efficient, circular economy model for second-home and post-disaster settlements. Full article

The application of volumetric modular construction using Cross-Laminated Timber (CLT) has emerged as a sustainable and efficient alternative to traditional building methods, especially in residential and mid-rise structures. However, the widespread adoption of this technology remains limited due to the lack of standardized inter-modular connection systems. This paper presents a comprehensive state-of-the-art review of inter-modular connections used in volumetric CLT modular buildings. This review aims to evaluate the inter-modular connections by developing performance objectives and identifying gaps in knowledge of volumetric CLT inter-modular connections. It begins with an overview of global CLT modular construction trends, highlighting geographic distribution, structural demands, and environmental hazards such as seismic and wind exposure. Seven representative connection systems were identified from the literature and assessed using a multi-criteria framework comprising structural performance, manufacturing feasibility, on-site construction efficiency, and experimental and numerical evaluation. Each connection was scored according to defined evaluation metrics, and the results were provided to identify key strengths and limitations. The top-performing systems demonstrated superior resilience, modular adaptability, and validation through experimental testing and simulation. The paper identified critical research gaps, including limited performance data available for seismic applications, challenges in disassembly and reuse specifications, and the need for adaptable, damage-tolerant systems to enhance building structural performance. These findings provide a reference evaluation methodology for future development of inter-modular connections, to expand the applicability of volumetric CLT modular construction in moderate and high seismic and wind hazard regions. Full article

Timber, as a renewable material, could reduce reliance on conventional construction materials such as reinforced concrete, thereby lowering carbon emissions. Its light weight, structural reliability, and efficiency in on-site assembly make it well suited to modular systems, which benefit from standardized components in both smaller- and larger-scale projects. However, existing research related to timber construction often emphasizes specific technical or performance issues, while systematic investigation of the timber module as a core building unit remains limited. This study adopts a multi-layered framework for circular modular timber construction, integrating design, structural, prefabrication and reuse perspectives to investigate timber modules, where each layer builds upon and interacts with the others. Through selected cases, the analysis characterizes how modules of different scales and forms are generated to meet spatial and functional needs, and highlights how prefabricated units support more optimized manufacturing. Furthermore, circular design principles are reinforced through reversible joints and design-for-disassembly techniques. The main findings highlight the proposed framework that positions modular units as central to design and construction, contributing to adaptable configurations and the reuse of timber components. Potential future research directions are highlighted, including the incorporation of quantitative evaluation indicators to support the assessment and implementation of circular design strategies. Full article

This study introduces and validates a miniaturized testing methodology for the complete orthotropic characterization of structural plywood, including out-of-plane directions that are typically difficult to access. Novel small-scale geometries were developed for tension and shear configurations, with compliance corrections applied to ensure accurate stress–strain responses. The method proved reliable and sensitive to mechanical differences arising from veneer architecture, adhesive type, and interfacial bonding. Two sets of 18 mm structural plywood panels—manufactured with distinct adhesive systems, one bio-based (F1) and one phenol-formaldehyde (F2)—were systematically tested under tensile, compressive, and shear loading in ten orthogonal configurations (T_x, T_y, T_z, C_x, C_y, C_z, τ_xy, τ_yx, τ_xz, τ_yz), following standards NCh 3617, EN 789, and ASTM B831. Tensile moduli were approximately twice the corresponding compressive values, while out-of-plane moduli reached only 6–11% of in-plane values. F1 exhibited higher stiffness in both tension and compression, particularly in transverse directions, due to thicker perpendicular veneers enhancing bending restraint and shear coupling. In contrast, F2 achieved greater peak shear strength owing to its more uniform veneer structure, which improved stress distribution and delayed interlaminar failure. Observed asymmetry between tension and compression reflected microstructural mechanisms such as fiber alignment and cell-wall buckling. The miniature-specimen data provide reliable input for constitutive calibration and finite-element modeling, while revealing clear links between veneer-thickness distribution, shear-transfer efficiency, and macroscopic performance. The proposed framework enables efficient, reproducible orthotropic characterization for optimized, lightweight, and carbon-efficient timber systems. Full article

The construction sector’s environmental footprint is driving the adoption of sustainable modular timber systems. The WikiHouse Skylark is a promising open-source model whose structural reliability depends on the performance of its critical plywood TIE joints. This study presents an experimental investigation of full-scale TIE joints fabricated from 18 mm Pinus radiata plywood in three variants: Standard (STD), Weather-Resistant (HR), and Fire-Resistant (FR). Monotonic tensile and shear tests were conducted to evaluate load–displacement behavior and failure modes. While the mean ultimate strengths varied between panel types, with HR highest in tension (7.7 kN) and FR highest in shear (8.2 kN), the most critical finding was the effect of the treatments on failure mode. The FR treatment induced a brittle fracture with significantly reduced ductility, in contrast to the more ductile tearing observed in STD and HR panels. This highlights a clear strength–ductility trade-off introduced by the fire-retardant treatment, a key consideration for structural design in modular timber construction. This dataset provides an essential empirical foundation for the numerical modeling and design guidelines of WikiHouse TIE joints, advancing the development of resilient and sustainable prefabricated housing. Full article

This paper presents LokAlp, a modular timber construction system invented and developed by the authors, inspired by the traditional Blockbau technique, and designed for circularity and self-construction. LokAlp utilizes standardized interlocking blocks fabricated from CLT and GLT off-cuts to optimize material reuse and minimize waste. The study explores the application of massive timber digital materials within an open modular system framework, offering an alternative to the prevailing focus on lightweight structural systems, which predominantly rely on primary engineered wood materials rather than reclaimed by-products. The research evaluates geometric adaptability, production feasibility, and on-site assembly efficiency within a computational design and digital fabrication workflow. The definition of the LokAlp system has gone through several iterations. A full-scale demonstrator constructed using the LokAlp final iteration (Mk. XII) incorporated topological enhancements, increasing connection variety and modular coherence. Comparative analyses of subtractive manufacturing via 6-axis robotic milling versus traditional CNC machining revealed a >45% reduction in cycle times with robotic methods, indicating significant potential for sustainable industrial fabrication; however, validation under operational conditions is still required. Augmented reality-assisted assembly improved accuracy and reduced cognitive load compared to traditional 2D documentation, enhancing construction speed. Overall, LokAlp demonstrates a viable circular and sustainable construction approach combining digital fabrication and modular design, warranting further research to integrate robotic workflows and structural optimization. Full article

Industrialized construction faces persistent fragmentation challenges that negatively impact project performance. Although there is consensus on the importance of integration, its effective adoption in industrialized construction, particularly for modular timber building companies, remains underexplored. This study examines how intra-organization fragmentation and stakeholder integration influence project performance through a combined empirical case study and theoretical simulation analysis. This study adopted a computational modeling strategy based on the Virtual Design Team (VDT) approach to simulate the organizational structure and process in a real-world industrialized timber building company. The VDT’s baseline results reveal significant rework from inadequate early integration among specialties and functional departments, increasing the project schedule. A revised scenario introduces horizontal and vertical integration by co-locating design and manufacturing team members and reducing the decision-making level. These adjustments substantially reduced rework in design phases and shortened the project duration below the original plan. The critical role of early collaborative involvement of all disciplines emphasizes that integrated organizational structures and processes are essential for ensuring reliable project outcomes in industrialized timber building companies. This research provides empirically grounded insights highlighting the strategic importance of integration in industrialized construction and establishes a validated modeling basis to guide practical interventions and future research on integration-driven improvements. Full article

Segmented timber shells present a novel building system that utilizes modular, planar building components to create lightweight free-form structures in architecture. Recent advancements in the research field of segmented timber shells pursue, among others, two fundamentally opposing research objectives. 1. The modularity of their building components facilitates the reuse of such structures in response to a changing built environment. 2. Advanced developments aim at establishing segmented timber shells as permanent building structures for sustainable architecture. This paper addresses the first research objective through the successful relocation of the BUGA Wood Pavilion in the context of the proposed methodology of Co-Design for circular construction. The methods and results involve integrative design and engineering processes and advanced quality assessment methods, including structural, geodetic, and physical properties for modular timber constructions. The BUGA Wood Pavilion serves as a building demonstrator for the presented research on segmented shells as lightweight, reusable, and durable timber structures. Full article

In recent years, the AEC industry has increasingly sought sustainable solutions to enhance productivity and reduce environmental pollution, with wood emerging as a key renewable material due to its excellent carbon sequestration capability and low ecological footprint. Despite significant advances in digital fabrication technologies for timber construction, on-site assembly still predominantly relies on manual operations, thereby limiting efficiency and precision. To address this challenge, this study proposes an automated on-site timber construction process that integrates a mobile construction platform (MCP), a fiducial marker system (FMS) and a UWB/IMU integrated navigation system. By deconstructing traditional modular stacking methods and iteratively developing the process in a controlled laboratory environment, the authors formalize raw construction experience into an effective workflow, supplemented by a self-feedback error correction system to achieve precise, real-time end-effector positioning. Extensive experimental results demonstrate that the system consistently achieves millimeter-level positioning accuracy across all test scenarios, with translational errors of approximately 1 mm and an average repeat positioning precision of up to 0.08 mm, thereby aligning with on-site timber construction requirements. These findings validate the method’s technical reliability, robustness and practical applicability, laying a solid foundation for a smooth transition from laboratory trials to large-scale on-site timber construction. Full article

The traditional timber architecture of Qiandongnan represents a rich cultural heritage. However, urbanization has led to the replacement of these structures with concrete and brick buildings, resulting in the loss of both functionality and cultural identity. To bridge the gap between traditional architecture and modern building needs, this study conducted field surveys to extract key design parameters from local structures, enabling the development of a modular framework for Structural Insulated Panels (SIPs) based on the dimensions of traditional dwellings. Four types of SIPs were developed using Chinese fir, OSB, EPS, and XPS, and their thermal performance and heat stability were evaluated through theoretical analysis and hot box testing. The results show that all specimens met the required heat transfer coefficient. The combination of OSB and XPS showed a slightly lower heat transfer coefficient of 0.60 compared to Chinese fir, which had a coefficient of 0.62. However, the Chinese fir–XPS combination provided the longest time lag of 6.34 h, indicating superior thermal stability. Due to the widespread use of Chinese fir in local construction and its compatibility with the landscape, this combination is ideal for both energy efficiency and cultural preservation. Full article

Prefabricated timber buildings offer a low-carbon approach that can help reduce the environmental impact of the building and construction sectors. However, construction materials such as manufactured timber products can emit a range volatile organic compounds (VOCs) that are potentially hazardous to human health. We evaluated 24 years (2000–2024) of peer-reviewed publications of VOCs within prefabricated timber buildings. Studies detected hazardous air pollutants such as formaldehyde, benzene, toluene, and acetaldehyde (indoor concentration ranges of 3.4–94.9 µg/m³, 1.2–19 µg/m³, 0.97–28 µg/m³, and 0.75–352 µg/m³, respectively), with benzene concentrations potentially exceeding World Health Organization indoor air quality guidelines for long/short term exposure. Most studies also detected terpenes (range of 1.8–232 µg/m³). The highest concentrations of formaldehyde and terpenes were in a prefabricated house, and the highest of benzene and toluene were in a prefabricated office building. Paradoxically, the features of prefabricated buildings that make them attractive for sustainability, such as incorporation of manufactured timber products, increased building air tightness, and rapid construction times, make them more prone to indoor air quality problems. Source reduction strategies, such as the use of low-VOC materials and emission barriers, were found to substantially reduce levels of certain indoor pollutants, including formaldehyde. Increasing building ventilation rate during occupancy is also an effective strategy for reducing indoor VOC concentrations, although with the repercussion of increased energy use. Overall, the review revealed a wide range of indoor VOC concentrations, with formaldehyde levels approaching and benzene concentrations potentially exceeding WHO indoor air quality guidelines. The paucity of evidence on indoor air quality in prefabricated timber buildings is notable given the growth in the sector, and points to the need for further evaluation to assess potential health impacts. Full article

Construction professionals work in silos and use traditional design and construction methods. The growing demand for rapidly built and high-quality construction is making off-site manufacturing mainstream. Studies have shown that collaboration among all stakeholders is a necessary component for success in the construction of such buildings. This multidisciplinary study of an existing concrete hotel aims to explore an alternative structural design in mass timber or volumetric modular construction. To this end, the reinforced concrete floor plan of Club Med de Charlevoix in Quebec, Canada, was used as a benchmark for two different structural systems. The first strategy investigated CLT (cross-laminated timber) and glulam columns to replicate the reinforced concrete system (column–slab), while the second involved maximum prefabrication (volumetric modular construction). Both mass timber and volumetric modular strategies can lead to a smaller carbon footprint. The main conclusion is that the plan should be designed from the outset to be either traditional or prefabricated since major changes are required if the choice is made to switch from one system to the other. Moreover, when structural systems maximize off-site construction, such as volumetric modular construction, the various professions need to be included during early planning. This is necessary to avoid task duplication and prevent the neglect of considerations such as manufacturable dimensions and partition organization. Full article