Trees integrated into buildings and dense urban settings have become a trend in recent years worldwide. Without a thoughtful design, conflicts between green and gray infrastructures can take place in two aspects: (1) tree crown compete with living space above ground; (2) built underground environment, the other way round, affect tree’s health and security. Although various data about urban trees are collected by different professions for multiple purposes, the communication between them is still limited by unmatched scales and formats. To address this, tree information modeling (TIM) is proposed in this study, aiming at a standardized tree description system in a high level of detail (LoD). It serves as a platform to exchange data and share knowledge about tree growth models. From the perspective of architects and landscape designers, urban trees provide ecosystem services (ESS) not only through their overall biomass, shading, and cooling. They are also related to various branching forms and crown density, forming new layers of urban living space. So, detailed stem, branch and even root geometry is the key to interacting with humans, building structures and other facilities. It is illustrated in this paper how these detailed data are collected to initialize a TIM model with the help of multiple tools, how the topological geometry of stem and branches in TIM is interpreted into an L-system (a common syntax to describe tree geometries), allowing implementation of widely established tree simulations from other professions. In a vision, a TIM-assisted design workflow is framed, where trees are regularly monitored and simulated under boundary conditions to approach target parameters by design proposals.

Abstract. Living Root Bridges (LRBs), grown by rural Khasi and Jaintia communities in Meghalaya (India), are the best known example of functional living architecture. Over 70 bridges, as well as ladders, pathways and platforms have been grown from a single species (Ficus elastica), using a collection of construction methods in regionally specific environmental conditions. In general, living architecture exhibits geometric complexity for which documentation and representation tools are yet to be established. Photogrammetric surveys provide data-rich point clouds which could be useful for analysis and design specific to living architecture. This study provides the first photogrammetric surveys of LRBs. Useful point clouds were produced for several bridges, as well as joint details. The method is found to have a range of benefits: providing detailed views, showing environmental conditions, and allowing for time analyses. The wider application of photogrammetry to living architecture is discussed, particularly with regards to Baubotanik structures and the improved documentation and representation of LRBs as a unique architectural typology. The need for developing a tool for topological model extraction, and possible methods therein is discussed.

Urban Microclimate Canopy is a digitally fabricated fiber glass structure supporting climbing plants in order to explore new ways of integrating vegetation in densely built urban environments. A prototype was designed and manufactured in the context of an interdisciplinary studio with master’s students following an approach of research by design. Varying the assembly of winding frames and fiber weaving syntax generates diverse geometric shape and structural performance. For two short-term exhibitions, ivy plants were temporarily installed in the structure. This first step was followed with a reflection of systematic integration of the growth processes of climbing plants and parametric design. An iterative solution is given, consisting of a feedback loop linking the design of the technical structure, the simulation of plant growth, and the simulation of the environmental effects of the hybrid structure. To achieve this a novel framework for simulating twining plant’s growth on network-like structures is presented: external stimuli define a cone-shaped circumnutation space (searching space model) which results in a climbing path (climbing steps model). The framework is constructed to integrate improved individual functions (such as stimuli of circumnutation) for better simulation results. To acquire more knowledge about interactions between the plants and the fiber structure, the prototype was installed permanently and planted with three different climbing plants, representing different climbing mechanisms.

Faced with the environmental challenges posed by climate change, architects are creating nature-based solutions for urban areas, such as transforming living trees into artificial architectural structures. In this study, we have analyzed stem pairs of five tree species conjoined for more than eight years by measuring the stem diameters below and above the resulting inosculation and by calculating the respective diameter ratio. Our statistical analyses reveal that Platanus x hispanica and Salix alba stems do not differ significantly in diameter below inosculation. However, in contrast to P. x hispanica, the diameters of the conjoined stems above inosculation differ significantly in S. alba. We provide a binary decision tree based on diameter comparisons above and below inosculation as a straightforward tool for identifying the likelihood of full inosculation with water exchange. Moreover, we have compared branch junctions and inosculations by means of anatomical analyses, micro-computed tomography, and 3D reconstructions showing similarities in the formation of common annual rings that increase the capacity for water exchange. Due to the highly irregular cell arrangement in the center of the inosculations, cells cannot be assigned clearly to either of the stems. In contrast, cells in the center of branch junctions can always be attributed to one of the branches.

Living architecture, changing in structure with annual growth, requires precise, regular characterisation. However, its geometric irregularity and topological complexity make documentation using traditional methods difficult and presents challenges in creating useful models for mechanical and physiological analyses. Two kinds of living architecture are examined: historic living root bridges grown in Meghalaya, India, and contemporary ‘Baubotanik’ structures designed and grown in Germany. These structures exhibit common features, in particular network-like structures of varying complexity that result from inosculations between shoots or roots. As an answer to this modelling challenge, we present the first extensive documentation of living architecture using photogrammetry and a subsequent skeleton extraction workflow that solves two problems related to the anastomoses and varying nearby elements specific to living architecture. Photogrammetry was used as a low cost method, supplying detailed point clouds of the structures’ visible surfaces. A workflow based on voxel-thinning (using deletion templates and adjusted p-simplicity criteria) provides efficient, accurate skeletons. A volume reconstruction method is derived from the thinning process. The workflow is assessed on seven characteristics beneficial in representing living architecture in comparison with alternative skeleton extraction methods. The resulting models are ready for use in analytical tools, necessary for functional, responsible design.