RecycleBIM project: Product Data Template and LOIN specifications
The RecycleBIM project promotes the circularity of construction materials starting from the definition of Product Data Template and LOIN specifications. Find out more in this interesting article!
The philosophy of reuse has finally spread to the construction sector. Minimizing resource waste, starting from the design phase and also planning for demolition, is a new challenge that technicians can no longer avoid.
A new perspective, therefore, that looks towards a very delicate phase of a building’s life cycle, namely its decommissioning at the end of its life cycle.
This approach aims to better manage the end-of-life of constructions, intervening in the planning of reuse and recycling of products and construction materials obtained on-site following demolition.
The topic is extremely interesting and very current, not only because it aims for full efficiency in construction processes (and demolition, indeed!), but especially for its beneficial implications in terms of environmental sustainability.
ACCA software is actively and proactively contributing to the cause, providing experience, resources, and technologies in support of the RecycleBIM project, an important multinational and multi-stakeholder initiative aimed at developing an integrated framework for the circularity of construction materials.
To learn more, read also RecycleBIM: a step forward towards the circularity of construction materials.
Contents
BIM and Material Reuse
The efficient management of construction and demolition waste (“Construction and Demolition Waste”, CDW) poses a critical challenge for achieving environmental sustainability goals and waste reduction.
The use of BIM methodology, through the production and management of digital 3D models, and the development of an integrated system for planning and utilizing BIM management tools represents a significant turning point in promoting the circularity of construction materials, which is the cornerstone of the RecycleBIM project.
Among the main objectives of RecycleBIM are:
- the digitalization of material management: creation of BIM models that incorporate data related to material circularity, including reuse metrics, recyclability, and environmental impact;
- the optimization of demolition processes: implementation of workflows that promote selective deconstruction and data-driven strategic planning;
- promotion of interoperability: use of open standards such as the IFC schema to ensure information exchange between different software platforms.
To pursue these objectives, it was necessary, first and foremost, to start with the definition of:
- product data templates (Product Data Template): developed based on the information requirements regarding circularity, these templates will provide a detailed guide for managing data related to materials;
- LOIN specifications (Level of Information Need): related to the main construction elements, these specifications will support life cycle assessment (LCA), energy audits, demolition planning, life cycle costing (LCC), as well as the development of inventories of reusable or recyclable materials, using BIM methodology with application tools based on IFC format files.
In this article, we will delve into these two aspects.
Comparing circular and linear economy showing product life cycle
Product Data Templates
Structuring construction product data in a standardized and machine-readable way is the first step towards promoting material circularity. PDTs (Product Data Template) are essential for exchanging information throughout the building lifecycle and enabling processes such as recycling and sustainable management of demolition waste. However, to maximize their effectiveness, it is necessary to harmonize them with international regulations and ensure their adaptability to local contexts.
The concept of Product Data Template is already addressed in existing regulations, particularly in the ISO 23386 and ISO 23387 (2020) standards, developed by the CEN/TC442 committee. A PDT represents a description of the essential information about a product, used for information exchanges during the planning, design, construction, or management phases of buildings. The properties defined in the PDT can be grouped by usage domain (e.g., performance or maintenance data) or by type of characteristics (geometry, environmental indicators).
However, currently existing datasets for construction products do not adequately standardize the alphanumeric data necessary for the circularity of construction materials. There is no comprehensive definition of the structure, type, and quantity of data required to promote circularity. This issue is attributed to the lack of specific regulatory frameworks and a poor understanding of the informational needs of stakeholders.
Structure of a Product Data Template
The PDT data is organized in a hierarchy that includes model entities (e.g., windows, doors, etc.), properties, and attributes.
Properties describe the characteristics of an object, while attributes assign specific values to those properties (e.g., the surface area of a wall). The steps to create a PDT include collecting and normalizing parameters, organizing them into categories (e.g., geometric data, sustainability data), and structuring them.
A crucial aspect is to keep Product Data Templates updated through feedback from industry professionals and ensure the readability of information through connections to interoperable data dictionaries.
For circular workflows, PDTs become essential in associating materials and construction products with their recyclability, reusability, or responsible disposal. There are already proposals, such as the “Product Circularity Datasheet” (PCDS), which include specific properties for circularity (composition, disassembly and reuse instructions, etc.). These solutions must also be adequate in terms of interoperability to ensure readability, exchange, and management over time by all stakeholders.
Definition of the Level of Information Need (LOIN) in the RecycleBIM Project
Another fundamental aspect of the RecycleBIM project was the definition of the Level of Information Need (LOIN) which establishes the granularity and level of detail of the information to be associated with each object in the model, necessary for each phase of the project lifecycle. Based on the EN 17412-1 standard, the LOIN has been applied in various contexts:
- geometric modeling: 3D representations of building elements, with specifications on geometric complexity for material quantification;
- alphanumeric data: use of Product Data Templates (PDT) to ensure machine readability and uniformity of information;
- documentation: linking datasets to environmental product declarations (EPD) and other documentary sources to support the assessment of circularity.
The level of detail required for deconstruction may vary based on needs and can range from a simplified representation, to obtain a rough quantification, to a higher level of detail for a more detailed analysis of materials.
The concept of granularity in LOINs
Geometric Modeling
The geometric representation of components mainly occurs in 3D to allow for the quantification of materials based on their volume. However, in some cases, such as for windows or doors, 3D detail may not be necessary, and 2D representations (surface) may suffice to facilitate quantification.
The geometry must be sufficiently detailed to allow for the quantification of materials and understanding of their characteristics, without the need for excessively complex and detailed modeling intended for visualization.
If, in fact, a building is considered a resource for material recovery, its digital representation must allow for accurate management of individual components, both at the material and product level. For example, when dealing with products made of a single material (such as cement or coatings), the representation of the material and geometry coincides. However, in the case of products made of heterogeneous materials, the management of information must be more detailed and differentiated, as the separation of materials and their recovery requires an integrated approach that combines information related to both materials and products.
For instance, the geometry of a wall can be represented as a simple shape (rectangular) that defines the outer shape, without going into details regarding the connections between elements. However, if the connections between components (such as in the case of a roof with a wall) affect the quantity of material, they need to be represented in greater detail.
Alphanumeric Data
Each object in the BIM model must be uniquely identified through:
- Code derived from a standard schema, for example, using classifications such as:
- Association with the appropriate IFC class, for example:
- IfcWall for walls;
- IfcDoor for doors;
- IfcWindow for windows;
- etc.
This standardized identification is crucial to ensure that data can be used and shared unambiguously among different actors and software.
For each component of the model, it is also essential to include details about the materials that compose it, including:
- type of material: specify whether it is cement, glass, metal, wood, plastic, etc.;
- material characteristics: total weight and volume;
- recycled content: the percentage of recycled material present in the component;
- chemical treatments: any processes or substances applied to the material (e.g., paints or sealants);
- environmental data: link the material to sustainability declarations such as:
- EPD (Environmental Product Declaration): provides information on the environmental impact of the material throughout its lifecycle;
- DoP (Declaration of Performance): declaration on the technical and environmental performance of the material.
Finally, circularity information is also necessary to facilitate the recovery and reuse of materials, such as:
- traceability of materials and components: information about the manufacturer, year of manufacture, conditions of use;
- links to secondary markets: each component must be documented so that it can be easily integrated into databases or marketplaces for recovered materials;
- material status: specify whether a material is reusable without treatment, recyclable after processing, or to be disposed of in a landfill.
Use of Product Data Template (PDT)
To organize the alphanumeric data of objects, making them readable by both humans and machines, it is advisable to use PDT, standardized templates that include:
- mandatory information: minimum data necessary to identify and evaluate the object;
- optional properties: additional information useful for specific analyses (e.g., thermal insulation, structural resistance).
PDTs are in line with international standards such as ISO 23387, which promotes the structuring of data for interoperability.
Furthermore, a data dictionary is used to ensure that terms and alphanumeric properties are uniquely defined and standardized. This ensures:
- consistency in terminology;
- interoperability between platforms.
Alphanumeric information is directly integrated into the BIM model or its related databases. For example:
- BIM object attributes: each wall, door, or window in the model will have an associated set of alphanumeric information visible directly on the object;
- tables and data sheets: alphanumeric data can be exported to spreadsheets or tables for external analyses.
In summary, alphanumeric content represents the core of the documentation for demolition planning and material recovery as it:
- improves material traceability;
- facilitates interoperability between systems;
- enables reuse and recycling, contributing to sustainability and circularity goals.
Documentation
In this context, documentation is not limited to recording alphanumeric or geometric information but also includes a range of information that supports the proper management, evaluation, and planning of demolition and recycling activities. Documentation can encompass a variety of information ranging from photography to environmental analysis of materials, and is essential to facilitate the transition to more sustainable and circular construction.
1. Types of documentation required
- Photographs and site scans
Photographs of the building or its components: images are visual tools that allow documenting the current state of the building before demolition. Photographs serve to highlight any particular features, such as the arrangement of components, the condition of materials, and accessibility to different areas.
These images can be uploaded to the BIM model as links to the respective alphanumeric resources, making it easier to visually reference the components described in the model.
3D scans (e.g., via laser scanning or photogrammetry): a three-dimensional scan of the site provides an accurate and detailed representation of the building, highlighting the geometry and exact location of objects to be demolished. These scans are essential for having a solid geometric database for demolition planning. - Historical and project documentation
Historical data of materials and components used: historical documentation may include details about the construction of the building, such as the type of materials used, construction methods, any treatments applied over time, etc. This information is crucial for determining the recycling potential of materials or the presence of hazardous substances (such as asbestos, toxic paints, etc.).
Original architectural plans and diagrams: the original plans of the building can be used to better understand the layout of spaces and the load-bearing structure. These documents are also important for determining how building components were assembled and for designing the demolition safely and efficiently.
Maintenance and inspection reports: reports related to maintenance interventions carried out over time can reveal the conservation status of certain structures and materials, such as the reinforcement of foundations or roofs, or the use of particular waterproofing technologies. This data can influence decisions on demolition or recycling methods.
2. Environmental Documentation
- Environmental Product Declarations (EPD) – EPDs (Environmental Product Declarations) are voluntary declarations that provide information on the environmental impact of a material or product throughout its life cycle, from production to disposal. In the context of a building to be demolished, the inclusion of EPDs provides details on:
- the impact of the raw materials used (for example, the CO2 emissions associated with the production of cement or steel);
- the durability and performance of materials throughout their useful life;
- disposal or recycling options, for example, whether it is easily recyclable or if it must be treated in a specific way to reduce environmental impact.
- Declaration of Performance (DoP) – The Declaration of Performance (DoP) provides specific information on the performance characteristics of a building material or component, such as structural strength, thermal or acoustic insulation, durability, fire resistance, and other technical characteristics. This data is particularly important for:
- assessing whether a building component can be reused without modifications;
- identifying materials that may require specific treatments before being reused.
3. Documentation for Demolition Planning
- Documentation for “lean deconstruction“ – Lean deconstruction is an approach that focuses on optimizing demolition processes to reduce costs, time, and waste. To implement this approach, the following are needed:
- detailed plans for material disposal and recovery;
- scheduling of demolition phases.
4. Links between documentation and BIM model
The documentation must be linked to the BIM model so that all alphanumeric, geographical, and historical information is accessible in real-time:
- photographic link to components in the BIM model: images and scans can be linked to individual components, allowing technicians to view the physical appearance of the object directly within the digital model;
- integration of environmental declarations and material information: EPD and DoP documents can be linked to objects in the BIM model for easy consultation during the demolition design phases.
5. Creation of a materials database
Once the materials and components of the building have been identified, a central database can be created to monitor:
- the availability of materials for reuse;
- the composition and quality of recyclable materials;
- opportunities to resell or make materials available for future use.
These are the essential initial steps to start a project for managing, reusing, recycling, or disposing of materials from demolitions.
