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Although widely recognized as imperative for reducing global emissions and the amount of waste generated by the architecture, engineering, and construction (AEC) sector, a large-scale shift from a linear to a circular economy has not yet happened in practice. This paper highlights practitioners’ needs for implementing circularity in the AEC sector in Switzerland, and how digital platforms could support it. We hosted two workshops with industry practitioners in the Swiss AEC sector to find out their needs from academia, government, and industry to implement such a shift. The first workshop revealed a need for digital reuse platforms, so we focused a second workshop specifically on digital platforms. Results from the second workshop made clear the need for better practices of gathering data and integrating platforms. Financial incentives, social innovation, policy measures, and digital tools were also identified as necessary to increasing circularity in the sector. Our findings reveal the promising potential of digital technologies and stakeholders’ networks to better capture data on building products and methods for extending their life cycle.

Heutzutage werden viele Stahlbetonbauten, die meist keine oder nur geringe strukturelle Defekte aufweisen, aus sozioökonomischen Gründen abgerissen. Wenn die Erhaltung eines bestehenden Gebäudes nicht möglich ist, erlaubt die Wiederverwendung der tragenden Bauteile in einem neuen Projekt, die schädlichen Umweltauswirkungen des Rück- und Neubaus zu verringern. Die Bauteile des obsoleten Gebäudes werden dabei sorgfältig demontiert, ohne sie zu Schutt zu zerkleinern. Sie werden gereinigt, möglicherweise repariert oder eingepasst und wiederverwendet, wobei ihre ursprüngliche Geometrie und ihre Eigenschaften so weit wie möglich erhalten bleiben. Die Anwendung dieser alternativen Strategie erfordert Änderungen im Planungsprozess der Abriss- und Neubauprojekte. Als Grundlage dafür muss das obsolete Bauwerk inventarisiert und analysiert werden, um die mechanischen und geometrischen Eigenschaften sowie die Dauerhaftigkeit der Stahlbetonbauteile zu bestimmen und ihre Wiederverwendbarkeit zu beurteilen. Das vorliegende Dokument beschreibt eine Methodik zur Beurteilung der Wiederverwendbarkeit und ein Verfahren für die Bestandsanalyse eines Stahlbetonbauwerk, das demnächst rückgebaut werden soll. Um den Planern beim Prüfen der verschiedenen Wiederverwendungsmöglichkeiten für ein Bauteil zu helfen, wird zunächst ein Werkzeug zur Beurteilung der Wiederverwendbarkeit vorgestellt. Es basiert auf den vorhandenen Schäden des Bauteils, seiner zukünftigen Nutzung und den für die Instandsetzung der Bauteile erforderlichen Massnahmen. Die Schadensbewertung wird vor dem Rückbau des Spendergebäudes durchgeführt. Die Nutzungsklasse - die die künftige Beanspruchung des Bauteils ausdrückt - und die Massnahmenklasse - die den Unterhalt und die nötigen Anpassungen des Bauteils beschreibt - hängen vom Bau des Empfängergebäudes ab. Nach der Klassifizierung der Schäden, Nutzung und Massnahmen eines Bauteils ergibt sich der Wiederverwendbarkeitsgrad, der eine Empfehlung für die Wiederverwendung und die damit verbundenen Kontrollen im Empfängergebäude ausdrückt. Diese Methodik zur Beurteilung der Wiederverwendbarkeit soll die Subjektivität der Analyse des Wiederverwendungspotenzials von Stahlbetonbauteilen verringern. In diesem Bericht werden die Schritte zur Durchführung einer vollständigen Bestandsanalyse von Stahlbetonbauwerken und deren Bauteilen beschrieben. Die Bestandsanalyse sammelt alle Informationen, die zur Beurteilung und Planung der zukünftigen Wiederverwendung der Bauteile erforderlich sind: Kategorisierung und Quantifizierung der Bauteile, Einstufung der vorhandenen Schäden, Untersuchungen der Geometrie und der Materialeigenschaften sowie Ermitteln weiterer Merkmale (Ästhetik, Zugänglichkeit, Tragwiderstand, Umweltauswirkungen). Diese systematische Methodik hat zum Ziel, die Subjektivität einer solchen Analyse zu verringern. Die hier beschriebenen Methodiken und Verfahren ermöglichen es, den Rückbau eines veralteten Stahlbetonbauwerks zu planen und dabei Mittel anzuwenden, die die Wiederverwendung der Bauteile mit dem grössten Potenzial begünstigen. Sie liefern auch die Informationen für die vorläufige Planung eines Empfängerbauwerks. In späteren Planungsphasen können zusätzliche Untersuchungen am Bestand erforderlich sein., See also English version. DOI: 10.5281/zenodo.7457909

Today, many reinforced concrete structure, most of the time with no or small structural disturbances, are demolished for socio-economic reasons. When the preservation of an existing building is not possible, reusing the structural component in a new project is a strategy that allows the diminution of the detrimental environment impacts of deconstruction and new construction. The components of the obsolete building are carefully dismantled without being crushed. They are cleaned, possibly repaired or trimmed and reused while maintaining as much as possible their pre-existing geometry and properties. Adopting this alternative strategy implies changes in the design processes of the demolition and new construction projects. As a starting point, the obsolete existing structure must be inventoried and assessed to define the mechanical and geometrical properties as well as the durability of its reinforced concrete components and to evaluate their reusability. The present document describes a reusability assessment method and a resource assessment protocol for a soon-to-be deconstructed RC structure. To help the designers evaluate the different reuse options for a component, a reusability assessment tool is first presented. It is based on the pre-existing damages of the component, its future use and the intervention required to rehabilitate the components. The damage assessment is conducted before the deconstruction of the donor building. The use class – expressing the structural demand for the component – and the intervention class – describing maintenance and modifications on the component – depend on the design of the receiver building. Once the damage, use and intervention of a component have been classified, the reusability grade is obtained, expressing recommendation for the reuse and the related monitoring in the receiver structure. This reusability assessment tool is intended to reduce the subjectivity of the assessment of reuse potential of RC components. This report then describes the steps to carry out the complete resource assessment of reinforced concrete structures and their components. The resource assessment collects all information needed to evaluate and plan the future reuse of the components: classification and quantification of the components, grading of their pre-existing damages, investigations on their geometrical and material properties and evaluation of their qualities (aesthetics, accessibility, resistance, environmental impact). This systematic methodology aims at reducing the subjectivity of such an assessment. The methods and protocols described herein allow planning the deconstruction of an obsolete RC structure using methods that will subsequently facilitate the reuse of the components with the most potential. They also give the information for preliminary designs of a receiver structure. In later design stages, additional investigations on the stock might be required., See also German version. DOI: 10.5281/zenodo.7457954

The Lagerhalle Erlenmatt Ost is a 3-story building (basement, ground floor and two upper floors) used for food storage, located in Erlenmatt district in Basel and erected in 1975. Cast-in-place reinforced concrete (RC) slabs, walls, and mushroom columns form the main load-bearing structure of the building. The self-supporting facade is made of lightweight expanded clay aggregate (LECA) concrete panels. The deconstruction of this building is planned, thus making available a large amount of RC components composing the structure and the facades. Little-known and rarely implemented, the reuse of concrete components from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reassembled with little transformation in a new project, maintaining their shapes and structural properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural components of the Lagerhalle Erlenmatt Ost, focusing on their potential value for reuse. Interest is mainly in the precast LECA concrete facade panels, but cast-in-place RC components are briefly included. The assessment methodology, detailed in a complementary report, allows identifying all properties needed to evaluate the potential for reuse of a RC component: geometry, material properties, resistance, current condition, accessibility, future durability, aesthetics and environmental impacts. After reviewing available reports and drawings on the building, onsite visits are carried out to complete the information and visually inspect the structural components. During the inspection, the components are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The building is made up of approximately 4 700 m3 of material constituting the load-bearing system, with approximately 450 m3 of precast LECA concrete and 4 250 m3 of cast-in-place concrete. The LECA panels are damaged and are assessed as unsuitable for structural reuse. The other components of the building load-bearing structure are considered in good condition by a first preliminary visual inspection. However, they would require further detailed investigations to gather all data needed to plan a potential future reuse. The inventoried components are divided into 5 categories: (1) facade components; (2) slab components; (3) wall components; (4) column components; and (5) staircases. For each of these categories a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each component types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq and kWhoil-eq) for fabrication and demolition of the components is also calculated. This document should serve as a base for designing and planning future reuse applications for the concrete components extracted when deconstructing the Lagerhalle Erlenmatt Ost. The information presented here will help planners to prioritize the reuse strategy on the components in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.

Concrete accounts for the largest share of worldwide building material use and waste generation, with cement production being responsible for approximately 9% of global anthropogenic CO2 emissions. A currently untapped strategy to significantly reduce these environmental impacts consists in reusing reinforced concrete (RC) elements in new load-bearing applications. This paper presents a new design-and-build concept to reuse cast-in-place RC wall and slab elements sourced from obsolete buildings. The applicability of the proposed paradigm is demonstrated through a prototype: a 10-m spanning post-tensioned segmental arch made of 25 reclaimed concrete blocks. The paper illustrates the complete workflow, including the sourcing of the blocks through sawing and the prototype assembly. A comparative Life Cycle Assessment shows that the prototype structure has a significantly lower environmental impact than equivalent designs made of new material.

About 9% of anthropogenic greenhouse gas emissions worldwide are due to the production of cement, key constituent of concrete. Concrete also contributes to a large share of demolition waste, usually coming from building structures that are discarded because of functional obsolescence rather than of technical deficiency. Current practice for treating end-of-life concrete is to landfill or crush it into aggregates used in new concrete mixes. Instead, a little-explored strategy consists in extending the service life of concrete elements by reusing them in new constructions. Following this paradigm, this paper presents a proof-of-concept prototype that reuses blocks cut out of obsolete cast-in-place concrete walls for a new structural application: a 10 m-long post-tensioned segmented arch footbridge. The paper details the design, material sourcing, and construction processes while highlighting the unusual features of the approach. The structural behavior is verified with a finite element analysis model and validated by load testing. A comparative life cycle assessment shows that the arch construction presents a significantly lower global warming potential then recycled concrete (−71%) or steel (−74%) alternatives and is very competitive to a timber one (+9%). In conclusion, the project proves the feasibility of a new circular economy application for the construction industry, in which new and reliable concrete structures are built with little to no cement inputs.

The Triemli Personalh��user are three equal 15-story buildings located on the Z��rich Triemli Stadtspital campus and erected between 1964 and 1969. Cast-in-place reinforced concrete (RC) slabs and walls form the building cores and their surrounding corridors. The rooms are arranged around these cores. The load-bearing intermediate walls, made of prefabricated masonry, support thin precast slabs used as permanent forms. A RC layer is cast over these precast slabs and connects the room slabs with the cast-in-place slabs of the corridors and cores. The self-supporting facade consists of precast RC panels. The City of Z��rich plans the deconstruction of these three buildings, thus making available a large amount of RC elements composing the structure and the facades of these buildings. Little-known and rarely implemented, the reuse of concrete elements from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reused without many transformations in a new project, maintaining their shapes, technologies, and mechanical properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural elements of the Triemli Personalh��user, focusing on their potential value for reuse. Both precast and cast-in-place RC elements are included. They are part of the load-bearing structure or are self-supporting such as the precast facade elements. The proposed methodology allows identifying all properties needed to evaluate the potential for reuse of an element: geometry, material properties, current condition, aesthetics, accessibility, resistance, future durability and environmental impacts. After reviewing available reports and drawings on the buildings, onsite visits are carried out to complete the information and visually inspect the structural elements. During the inspection, the elements are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The investigations are completed with destructive and non-destructive testing of the material properties. Together, Buildings A, B and C are made up of approximately 7 000 m3 of materials constituting their load-bearing system, with approximately 2 500 m3 of precast concrete, 3 400 m3 of cast-in-place concrete and 1 100 m3 of masonry. Of this total, approximately 4% of the volume is dropped from the analysis due to the bad condition of the elements, namely the balcony slabs, the roof slab, and the external stairs. The other elements are in a good or acceptable condition and ae inventoried and analysed in detail. The inventoried elements are divided into 5 categories: (1) facade elements; (2) slab elements; (3) wall elements; (4) column elements; and (5) staircases. Each of these categories are subdivided into a certain number of element types for which a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each element types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq) for fabrication and demolition of the elements is also calculated. The results of the investigation on material properties confirm sufficient compressive strength for all elements. The carbonation depths measured on the cores are lower than the cover thickness of the reinforcement. Thus, the concrete is not carbonated in the reinforcement areas and the risk of corrosion is kept low, insuring a good durability of the elements. This document should serve as a base for designing and planning future reuse applications for the concrete elements extracted when deconstructing the Triemli Personalh��user. The information presented here will help the planners to prioritize the reuse strategy on the elements in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.

The Triemli Personalhäuser are three equal 15-story buildings located on the Zürich Triemli Stadtspital campus and erected between 1964 and 1969. Cast-in-place reinforced concrete (RC) slabs and walls form the building cores and their surrounding corridors. The rooms are arranged around these cores. The load-bearing intermediate walls, made of prefabricated masonry, support thin precast slabs used as permanent forms. A RC layer is cast over these precast slabs and connects the room slabs with the cast-in-place slabs of the corridors and cores. The self-supporting facade consists of precast RC panels. The City of Zürich plans the deconstruction of these three buildings, thus making available a large amount of RC elements composing the structure and the facades of these buildings. Little-known and rarely implemented, the reuse of concrete elements from obsolete buildings in new projects is a sustainable approach that promotes a circular economy. When reusing, the components of obsolete buildings are carefully dismantled without being crushed. They are then cleaned, possibly repaired or trimmed, and reused without many transformations in a new project, maintaining their shapes, technologies, and mechanical properties. In addition to maintaining the embodied energy and history of the reused components, reuse allows the construction industry to reduce demolition waste, greenhouse gas emissions, and material consumption. This report is a preliminary resource assessment and aims at inventorying and assessing all structural elements of the Triemli Personalhäuser, focusing on their potential value for reuse. Both precast and cast-in-place RC elements are included. They are part of the load-bearing structure or are self-supporting such as the precast facade elements. The proposed methodology allows identifying all properties needed to evaluate the potential for reuse of an element: geometry, material properties, current condition, aesthetics, accessibility, resistance, future durability and environmental impacts. After reviewing available reports and drawings on the buildings, onsite visits are carried out to complete the information and visually inspect the structural elements. During the inspection, the elements are assessed with regards to their suitability for reuse and their condition is classified into a five-grade scale. The investigations are completed with destructive and non-destructive testing of the material properties. Together, Buildings A, B and C are made up of approximately 7 000 m3 of materials constituting their load-bearing system, with approximately 2 500 m3 of precast concrete, 3 400 m3 of cast-in-place concrete and 1 100 m3 of masonry. Of this total, approximately 4% of the volume is dropped from the analysis due to the bad condition of the elements, namely the balcony slabs, the roof slab, and the external stairs. The other elements are in a good or acceptable condition and ae inventoried and analysed in detail. The inventoried elements are divided into 5 categories: (1) facade elements; (2) slab elements; (3) wall elements; (4) column elements; and (5) staircases. Each of these categories are subdivided into a certain number of element types for which a complete factsheet is prepared, including pictures, drawings and useful information on their condition. The volume and weight of each element types are given, as well as their share of the total material volume. The embodied global warming potential (in kgCO2eq) for fabrication and demolition of the elements is also calculated. The results of the investigation on material properties confirm sufficient compressive strength for all elements. The carbonation depths measured on the cores are lower than the cover thickness of the reinforcement. Thus, the concrete is not carbonated in the reinforcement areas and the risk of corrosion is kept low, insuring a good durability of the elements. This document should serve as a base for designing and planning future reuse applications for the concrete elements extracted when deconstructing the Triemli Personalhäuser. The information presented here will help the planners to prioritize the reuse strategy on the elements in the best conditions, with the largest volume share and thus with the largest embodied global warming potential.

A travers une revue de la littérature, ainsi que 32 études de cas et des entretiens avec des praticiens, ce recueil: › synthétise les principes fondamentaux des deux approches; › documente et diffuse les retours d’expériences et les bonnes pratiques; › apporte aux entrepreneurs/entrepreneuses, concepteurs/conceptrices et maîtrises d’ouvrage des références techniques; › procure aux parties prenantes un bagage théorique à la pointe et détaillé ainsi qu’une série de référence pour aller plus loin; › esquisse les perspectives d’évolution et opportunités applicables au bâti suisse.

As the most widely used construction material worldwide, concrete is the main cause of greenhouse gas emissions, material depletion, and waste generation by the construction industry. Typically, concrete waste is crushed and, at best, reclaimed into recycled aggregate or used as gravel. This process is energy-intensive and results in a reduction in material properties. In contrast, the direct reuse of concrete elements from obsolete structures offers great potential for significantly reducing the environmental impact of new constructions. To be reused, concrete elements are carefully sawn out of soon-to-be-demolished buildings. Elements are then used without other major transformations for another service cycle in a new assembly. This paper analyses two recent projects in Switzerland that showcase innovative applications of concrete reuse: a post-tensioned segmented arch footbridge and a parking pavement. Both projects reuse blocks extracted from cast-in-place concrete buildings undergoing transformation or demolition. In this paper, environmental and economic analyses provide a comprehensive understanding of the alleviations and costs involved. Results are compared to those of alternatives with conventional construction methods. The two projects reusing concrete globally showcase a drastically lower environmental impacts for comparable or higher construction costs, hence calling for future developments of such new circular construction strategies.

ispartof: Frontiers in Built Environment vol:6 issue:57 pages:1-18 status: published

The design of doubly-curved systems called for innovative modelling techniques to evaluate the final geometry of the structure. They can simulate the behaviour of beams under large displacements. Even though it is never analysed, the deformation path is can be critical in such complex configurations. This paper analyses the potential of digital technologies to investigate the behaviour of beams under bending-torsion coupling in large deformation. In a first part, we will present the setup for an experiment, based on the use of robotic arms. The versatility of robotic arms allows to access complex configurations or loading paths, while controlling the test either in displacements or in forces. In a second part, an enhanced photogrammetry procedure is introduced. The aim is to retrieve the geometry of the beam even in the case of complex 3D shapes. The acquisition yields a point cloud representation of the beam. Finally, we propose a workflow to make the interaction with robotic arm, simple and efficient. The novel experimental setup aims at making possible the study of beams with complex form, under ever more complex force.

This case study applies life-cycle assessment methods to the preliminary design of an office building in order to quantify the benefits achieved when reusing its load-bearing components. Results show that the production of the load-bearing system would account for 40% of the global warming potential indicator. The slabs are responsible for 65% of the environmental impacts among all structural elements and should be considered for reuse first. Compared to traditional constructions built from first-use material, a fictitious reuse of undamaged load-bearing components over three consecutive use cycles would reduce the global warming potential indicator by 25%. The global warming potential of reuse is eventually computed according to three repartition methods, highlighting the need to separate the life-cycle footprints related to production, use, and end-of-life more systematically.

This paper presents an extension to the Combinatorial Equilibrium Modelling (CEM) design framework. So far, CEM gives the possibility to generate and explore multiple spatial equilibrium solutions in the early conceptual design phase. In addition to the form and force diagrams of graphic statics, CEM introduces a topological diagram, which allows to adjust the connectivity of a spatial strut-and-tie network in equilibrium, its combinatorial inner force state (tension-compression) as well as its metric values (such as element’s length or force magnitudes) in real time. In order to solve more specific design problems within the CEM framework, hence to guide design explorations, constraints-driven adaptation procedures have been developed. This paper describes how these interactive and automatic adaptation methods can be embedded in an overall structural design process containing alternating steps of lateral exploration and vertical adaptation. Moreover, the paper describes how design constraints can be transformed into objectives within non-linear optimization problems and which algorithms can be used to solve them.

This paper presents an extension of the graphic-statics-based framework called Combinatorial Equilibrium Modelling (CEM). CEM allows for the generation of topologically and combinatorially different spatial equilibrium solutions in the early explorative design phase. In addition to the form and the force diagrams, CEM introduces a topological diagram, which enables the possibility to easily adjust the connectivity of the structure, the combinatorial state (tension-compression) as well as the static action (product of each element’s length and its corresponding force magnitude) of its inner forces. Thanks to its planarity, the topological diagram is always visually readable, comprehensible and easy to control, even in case of complex spatial structures. This innovative approach has the potential to find novel spatial networks in which the intrinsic structural properties can be controlled by the designer with simple visual operations. Keywords: equilibrium, combinatorial state, topology, force-pattern-based design, form-finding, interactive structural design

Geometrical domains characterising the degrees of freedom of a structural system within the context of Maxwell’s reciprocal representation of force and geometry are likely to provide indicators of the constitutive elements of structural robustness. Structural robustness is defined as the “insensitivity to local failure”. This definition emphasises the structure’s capacity for force redistribution and the possibility of finding alternative load paths in a structure. Features linked to resistance and the redistribution of forces are likely to be modelled by load path, struts and ties or thrust lines, close to geometrical thinking. Since most methods proposed today for assessing the robustness of structures are based on probabilistic approaches, they are of limited interest for the design phase. Of the few approaches that have adopted a deterministic formulation, all provide a type of survey that is based on an in-depth analysis of the structure once it has been designed, according to specific scenarios. A central challenge should be to manage the issue of robustness earlier during the design process, or even to be able to interact with a model of the future structure in order to adjust the features of robustness. This paper explores the ability of geometrical domains to assess some of the relevant elements of structural robustness in terms of design in order to characterise the capacity of structures to redistribute forces. It compares indicators linked to the area of these domains. Based on case studies, this quantification of the structural provision is then compared with indices of deterministic and energetic criteria currently proposed in literature to quantify structural robustness.

This thesis introduces “constraint-based graphic statics”, a geometrical support for computer-aided structural design. This support increases the freedom with which the designer interacts with the plane static equilibriums being shaped. Constraint-based graphic statics takes full advantage of geometry, both its visual expressiveness and its capacity to solve complex problems in simple terms. Accordingly, the approach builds on the two diagrams of classical graphic statics: a form diagram describing the geometry of a strut-and-tie network and a force diagram vectorially representing its inner static equilibrium. Two new devices improve the control of these diagrams: (1) nodes — considered as the only variables — are constrained within Boolean combinations of graphical regions; and (2) the user modifies these diagrams by means of successive operations whose geometric properties do not at any time jeopardise the static equilibrium of the strut-and-tie network. These two devices offer useful features, such as the ability to describe, constrain and modify any static equilibrium using purely geometric grammar, the ability to compute and handle multiple solutions to a problem at the same time, the ability to switch the hierarchy of constraint dependencies, the ability to execute dynamic conditional statements graphically, the ability to compute full interdependency and therefore the ability to remove significantly the limitations of compass-and-straightedge constructions and, finally the ability to propagate some solution domains symbolically. As a result, constraint-based graphic statics encourages the emergence of new structural design approaches that are highly interactive, precognitive and chronology-free: highly interactive because forces and geometries are simultaneously and dynamically steered by the designer; precognitive because the graphical region constraining each points marks out the set of available solutions before they are even explored by the user; and chronology-free because the deductive process undertaken by the designer can be switched whenever desired. Applications cover the design of reticular systems — regardless of whether they are isostatic, indeterminate, prestressed, self-stressed or mechanisms — regular and irregular beams subject to bending, compression-only structures described by lines of thrusts, and structures that can be modelled with discontinuous stress fields. (FSA - Sciences de l'ingénieur) -- UCL, 2013

This paper presents a computer-aided environment aimed at assisting designers during the very first stages of the structural design process. It gives designers the opportunity to build and modify interactively geometric constraints that control the structural shape and its static equilibrium simultaneously and in an entirely graphical way. Following a brief contextualization, the paper presents the main features of the inner algorithms. Typical uses are then described in order to illustrate the wide range of applications and their practical benefits. As a result, it is argued that this environment opens up new opportunities for precognitive, chronology-free and highly interactive paradigms of structural equilibrium design.

The first geometrical definitions of any structure are of primary importance when considering pertinence and efficiency in structural design processes. Engineering history has taught us how graphic statics can be a very powerful tool since it allows the designer to take shapes and forces into account simultaneously. However, current and past graphic statics methods are more suitable for analysis than structural morphogenesis. This contribution introduces new graphical methods that can supplement the use of graphic statics during the primary establishment of both the structural shape and its mechanical behaviour. First an explanation is given of the underlying motivations, with a short reminder of traditional graphic statics, and then the proposed design process is outlined with two main concepts: geometric domains and equilibrated operations. Finally, some interesting applications are set out.