Markus Hudert

Increasing the use of wood as a construction material and implementing circular economy principles are possible ways of reducing the environmental impact of the building construction sector. However, with an increasing use of timber and mass timber products in buildings, the amount of wood production waste is increasing as well. Wood production waste is typically downcycled and not considered as a resource for construction. This is particularly questionable in the case of Cross-Laminated Timber (CLT). Compared to other types of engineered wood products, its production requires large amounts of raw material and results in large amounts of waste. In contrast to downcycling, upcycling CLT production waste bears the promise of preserving or even increasing the material’s value, which makes it economically more compelling. In this paper, we present a prototypical computational design and digital fabrication workflow that enables the use of CLT production waste in prefabricated assemblies, potentially to be used as wall or façade elements, ideally with modular qualities. We elaborate on how the application of this workflow enabled the design and construction of a full-scale demonstrator, which serves as a proof-of-concept, and share insights gained during and after its construction. Finally, the paper provides an overview of possible applications and discusses the adjustability of the workflows for other design principles and construction systems.

The field of artificial intelligence (AI) has recently attracted the attention of many disciplines due to the exceptional accomplishments and rapidly emerging possibilities. Architecture, a discipline traditionally skeptical of new technologies, is intrigued by the results achieved with generative neural networks. The emergence of new technologies in the field of generative artificial intelligence has led to numerous scenarios among architects about possible applications of these technologies in their practice. A large number of these scenarios are based on the functionality of commercially available Large Language Models and their application to text to image and image to image transformations. A smaller number of scenarios are based on specific applications of AI technologies through the development of real software solutions. The paper critically analyzes existing scenarios through a review of existing research and a description of software solutions. The focus is on the application of Generative Neural Networks and the paper provides an overview of the functioning of the basic classes of neural networks that make up this technology. An analysis of how artificial neural networks work shows that they all depend on the data set used to train them. Today's neural networks use an enormous amount of data, but even that is limited to what is available in electronic format. The main source of general knowledge is online encyclopedias, while expert knowledge is provided by published articles that have a certain level of reliability. Architects who are mistrustful of this technology need to understand that better results can only be achieved through higher-quality training data sets and that their protectively guarded knowledge also comes from studying the work of other architects.

A method for building slabs composed of discrete short timber slats is proposed. It involves simulating its principal stresses to locate and orient each building component. Those are assembled by a robotic arm in collaboration with a worker using an Augmented Reality head-mounted device. The prototype serves as a proof of concept and proved structurally viable, and future work involves interlocking the slats using halved joints and implementing a strategy to reuse wood production waste components as stock material.

When facing the increasing demands of the housing market and balancing the requirements of sustainable development in the construction sector, building design methods should practise material conservation and adopt carbon reduction measures to alleviate the current environmental burden through the implementation of a circular economy approach. Volumetric modular timber design is recognised as a practical application to test the feasibility of a waste-reduced approach. Driven by the aim of further improving volumetric modular timber construction and increasing its use in a circular economy framework, this paper presents a case study review of 60 modular timber building projects constructed using volumetric modules. The dimensions, the architectural and structural design, and the manufacturing and assembly processes of the three-dimensional modular units were assessed to explore their potential for contributing to a circular built environment. The results show that the similarly sized modular volumetric timber units have the potential to serve different functions, and to be reused in subsequent projects. The stacking design allows modular volumetric units to be reused in a way that supports function conversion and satisfies project coordination criteria. The case studies illustrate that modular timber buildings are increasingly used for flexible design solutions, and to meet carbon emission reduction targets. The analysis results can address prevalent misconceptions regarding modular wood construction, provide interested parties with a better understanding, and promote the use of modular volumetric timber units in general.

As part of the green transition, a current trend in the construction sector is to utilize more wood and lightweight composites, aiming at a reduction of the embodied energy in buildings. At the same time, with a focus on circularity and reuse, large-span structures are preferable, since they provide more flexibility for future uses of the building. The mix of large spans and lightweight structures pose a risk in terms of increased vibration levels. Hence, assessment of the vibroacoustic performance of a building is necessary in the early design stage to guide the designers towards useful solutions. This paper presents a computational framework for such assessment. While the framework is based on the combination of advanced digital tools for architectural design and rigorous finite-element modelling of the structure, a simple-to-use spreadsheet interface allows the non-experienced used to perform analysis. To provide an example, a small building made of cross-laminated timber has been analysed regarding its steady-state response to time-harmonic excitation on a floor. The paper demonstrates how representative acceleration levels can be achieved at a low computational cost.