BIM Interoperability: Dissemination and Collaboration in RecycleBIM

Adopting the BIM methodology in your professional activity means orienting towards advanced, collaborative, and multidisciplinary digital processes, based on information models capable of integrally representing all the physical and functional characteristics of a work. BIM is not simply an evolution of CAD, but a true paradigm shift in the management of information throughout the life cycle of a building or infrastructure.

Over time, the concepts underlying BIM have consolidated, evolving from an initial idea centered on a single model managed by one software, to a federation of interoperable models capable of communicating with each other even if developed with different tools and disciplines. This is where the key concept of interoperability comes into play.

To fully understand how these themes translate into practical applications, we will analyze the RecycleBIM case study in the following article, a European project that addresses BIM interoperability in relation to the circular management of construction materials, illustrating a concrete approach through the production of interoperable IFC models, developed in Revit and Archicad environments.

For further reading, see also:

• RecycleBIM: a step forward towards the circularity of construction materials.
• Product Data Template and LOIN specifications in the RecycleBIM project;
• Exchange Information Requirements: what is an EIR in BIM?;
• BIM Execution Plan (BEP): what is it and what is its purpose?

BIM maturity levels: towards iBIM

In the landscape of construction digitalization, several BIM maturity levels can be identified, each representing a phase of growth in the ability to manage and exchange data:

• Level 0: exclusive use of 2D CAD.
• Level 1: introduction of 3D elements but without real collaboration.
• Level 2: federation of separate models with controlled information exchange, often through open formats like IFC.
• Level 3 (iBIM): integrated data management with full interoperability, shared access to data, and advanced process automation.

Level 3, promoted for example by the British Digital Built Britain plan, does not overturn the concept of the federated model, but aims to improve the quality of data exchange and operational efficiency throughout the life cycle of the work.

Below we present the diagram on BIM maturity levels that represents the level of dissemination, utilization, and especially the exploitation of BIM’s potential.
It starts from CAD, which represents the lowest level (level 0), up to level 3 corresponding to iBIM.

Levels of collaboration and dissemination of BIM

The level 2 is characterized by a certain degree of data exchange capability between distinct models, each related to the main professional fields.

The subsequent step, level 3, which refers to a mature degree of utilization, and which will be achieved through 4 distinct phases (according to the document from the UK Government “Digital Built Britain – Level 3 Building Information Modelling – Strategic Plan”), does not change the current idea of the virtual model as a federation of models, but focuses entirely on a higher level of data exchange quality between them.

HM government

Detailed view of level 3 of BIM collaboration and dissemination

The quality of data exchange is, therefore, the direction in which the greatest effort is concentrated for the dissemination of BIM interoperability, both from a procedural perspective and in terms of software tools.

The issuance of international standards, guidelines, and indications with the coding of key documents for the organic execution of procedures and the methods for their drafting and minimum content are the efforts made to adapt the BIM methodology to various real cases.

It is evident how the issue of model overlap and their ability to communicate without loss of information, that is, interoperability, represents the cornerstone for the actual possibility of utilizing model federation.

Pas1192 Cycle

BIM and Interoperability: The Key to Success in the Construction Sector

Interoperability refers to the ability to exchange data between applications, BIM software, and platforms, allowing for standardized workflows and facilitating automation.

This is particularly important in the BIM environment, where each object contains not only geometry but also technical, environmental, temporal, economical, managerial data, and more.

This is not a new concept: the need for dialogue between applications designed for specific purposes but belonging to the same production chain has always been essential; for instance, consider the emergence of the DXF format for transferring graphic data in vector format between different software applications.

However, the urgency of this need has primary importance in the case of the BIM methodology, where the integration of different information is the very essence of innovation.

Moreover, the quality of the information to be exchanged goes well beyond simple graphic data, as the use of objects enables the management and transfer of information relating to materials, quantities, costs, timelines, energy analyses, and structural aspects, among others.

The issue of data exchange, therefore, has been the subject of great attention and efforts over time from research bodies, software manufacturer associations, industries, etc., constituting a true stand-alone technology that has evolved alongside the development of application software and its requirements.

Formats such as IFC (Industry Foundation Classes), developed by buildingSMART, are fundamental to ensure communication between different applications. Interoperability is not an accessory value; it represents the necessary condition to fully realize the potential of BIM in terms of sustainability, efficiency, and digitization.

The RecycleBIM Case: Interoperability in the Service of the Circular Economy

A concrete and advanced example of the application of BIM interoperability is represented by the European project RecycleBIM. The project addresses a highly relevant issue: the management of construction materials from a circular perspective, promoting reuse and recycling through digital tools based on BIM.

To support professionals, the project has produced an essential technical document, the Training kit for interoperability, a comprehensive and practical guide for the correct modeling and export of BIM models in IFC format, with particular attention to information about materials and their traceability.

An Operational Kit for IFC Modeling

The working team proposes a practical methodological approach to ensure interoperability and information quality in BIM models, in line with environmental and circularity requirements. Among the main contents of the interoperability documentation, we find:

• Classification of Use Cases for Material Representation
  The document identifies 5 modeling strategies depending on the nature of the building component and the type of material:
  • Single-material objects (e.g. masonry, partitions);
  • Layered elements (e.g. floors, roofs);
  • Composite components (modeled by parts or described alphanumerically);
  • Complex objects measurable in m² or m³ (e.g. fixtures);
  • Objects managed by unit (e.g. doors, prefabricated elements).

Recycle BIM use case | BIM modeling strategies for interoperability

A multilayer wall, when represented as a single element, can be decomposed into its material layers using the IfcBuildingElementPart entity.

The main object (the wall) contains the specific properties of the element (according to the WBS), while each part (material layer) contains the specific properties of the material.

If some layers are identified as reusable (for example, a facade cladding on a frame designed for deconstruction), the corresponding entity (whether it is IfcBuildingElementPart or a specific object like IfcWall or IfcCovering) hosts the specific properties of the element.

This classification allows for standardizing the digital representation of materials, facilitating their reading in different software and traceability during demolition or reuse.

• Modeling and Exporting with Revit and Archicad
  The chapter dedicated to modeling and exporting with the BIM software Revit and Archicad illustrates a complete and detailed workflow to ensure that the BIM model meets the interoperability requirements set by the RecycleBIM project. The goal is twofold: to ensure correct export in IFC4 format and to include all necessary information in the model for the circular management of construction materials. The document provides detailed instructions for two widely used BIM environments:
  • Autodesk Revit:
    • Modeling from point cloud;
    • Definition of multilayer elements (e.g., walls with structural, insulating, and finishing layers);
    • Attribution of properties required for waste management (EWC code, density, recyclability, etc.);
    • Export in IFC4 format with custom mapping (CDWMgmt_Pset);
  • Graphisoft Archicad:
    • Importing point clouds in .e57 or .xyz format;
    • Creating custom export sets via IFC Translator;
    • Mapping properties to materials and components, with layer decomposition;
    • Exporting according to RecycleBIM specifications, with data verification;
• Verification of the IFC Model
  Finally, it is recommended to verify the IFC files using viewer software (such as BIMVision), to ascertain the presence of the required properties, the correct classification of elements, and the geometric quality of the model. In particular:
  • check the correct assignment of levels to objects;
  • verify the presence of the required property sets (particularly CDWMgmt_Pset);
  • identify any geometric errors, distortions, or missed exports;
  • visually explore the structure of the IFC file before further validations.

Creation and Validation of the BIM Model with Edificius and usBIM.IDS

BIM interoperability is not just a technical challenge, but a fundamental requirement to ensure efficiency, traceability, and added value throughout the life cycle of a project. A practical example of effective implementation comes from the key role of ACCA software in the European project RecycleBIM, in the development of an informational BIM model aimed at managing construction and demolition waste (CDW), planning selective deconstruction, and conducting LCA/LCC assessments.

Created in Edificius, the model stands out for its high level of consistency with the principles of openBIM, thanks to the use of the IFC 4.3 format and the structuring of a customized informational set, aligned with the project’s standards.
To ensure real interoperability, careful management of the informational specification (EIR), consistent modeling with the levels of informational need (LOIN), and precise mapping of properties and entities are required. In line with these principles, the model developed by ACCA included the integration of layered parametric objects, with environmental, quantitative, and functional properties useful for supporting LCA analyses and energy forecasts.

Through the use of customized property sets (e.g., CDWMgmt_Pset) and adherence to IFC standards, each building component has been enriched with information about the materials used, the thicknesses of the various layers, physical performance such as conductivity and density, as well as the potential for reuse or recycling. All of this has been validated through IDS standards, which allowed for verifying the compliance of the data with the project’s informational requirements.
This experience demonstrates how a data-driven informational modeling process can translate into an interoperable model ready to be integrated into the digital flows of the circular economy.

The work carried out by ACCA software represents a successful application case that enhances and concretely implements the methodological guidelines developed by the University of Minho team. Thanks to an informational modeling approach based on interoperability, sustainability, and traceability criteria, it has been possible to demonstrate how theoretical principles can translate into real operational tools. BIM interoperability, in fact, should no longer be understood as an abstract concept, but as an indispensable requirement for generating reliable, intelligent, and integrable digital models in the decision-making and management processes of the construction supply chain.

From Interoperability to Sustainability: The Added Value of RecycleBIM

The work done within the RecycleBIM project demonstrates how the correct application of the IFC standard, combined with conscious modeling, can transform BIM into a concrete tool for the circular economy. Not only design and construction but also selective demolition, recovery, and valorization of materials can be managed digitally.

Thanks to a coherent approach, the Training kit for interoperability helps BIM professionals produce complete, interoperable informational models suitable for multiple applications: from LCA/LCC to marketplace platforms for reusable materials.

Conclusions

The RecycleBIM case study concretely demonstrates how it is possible to successfully address the challenges related to the exchange and use of BIM data, improving interoperability through the correct transformation of models into the IFC format. The modeling of a sample building with different software, following precise informational requirements and structured guidelines, has allowed for validating a robust approach to BIM modeling, perfectly aligned with the project’s objectives.

Adopting this method allows for obtaining coherent, complete, and reusable IFC files, reducing data transmission errors and promoting collaboration among heterogeneous actors and tools. The actions taken by RecycleBIM provide BIM professionals with practical tools and technical skills to produce high-quality interoperable models, essential for the transition to a more digital, efficient, and circular construction supply chain.

To support the implementation of the methodology, a video tutorial is also available that accompanies the technical document, offering an additional operational tool for those who wish to directly apply what has been illustrated.