Model Element Author (MEA) in BIM: Who and What Role?

Building Information Modeling (BIM) has transformed the way buildings and infrastructure are conceived, designed, and managed. Rather than serving as a simple three-dimensional representation, the BIM model functions as a comprehensive digital twin of the asset, integrating geometry, data, and processes throughout its lifecycle. This approach enables project teams to virtually design, coordinate, and validate a project before construction begins, significantly reducing errors, rework, delays, and costs.

However, the effectiveness of a BIM model depends on the quality and reliability of the information it contains. Since multiple disciplines—including architecture, structural engineering, and MEP systems—contribute to the same federated environment, clear ownership of model elements is essential to ensure consistency, accountability, and efficient collaboration.

This is where the Model Element Author (MEA) plays a critical role. The MEA is the individual or organization responsible for creating, developing, and maintaining specific model elements, ensuring that information is produced according to predefined requirements, project milestones, and agreed levels of development.

In this article, we will explore the role of the Model Element Author in detail, examining its responsibilities, its importance within the BIM process, and the contractual and organizational tools used to assign and manage authorship throughout the project lifecycle.

Building data before the material

What is the Model Element Author in BIM?

The MEA, acronym for Model Element Author, is one of the key figures within a BIM Project alongside the “Project BIM Manager” and the “Discipline BIM Lead”.

The Model Element Author is the professional involved in the BIM process and is responsible for producing the informational model of the work or parts of it.

The AIA Document G204–2022 defines the MEA as the entity or individual responsible for managing and coordinating the development of a specific Model Element based on the LOD required in relation to the specific project milestone.

The roles that occupy this position within a project delivery process can be more than one depending on the informational model that needs to be produced and the parts that will make it up. Generally, the MEA disciplines are:

• MEA Architecture;
• MEA Structure;
• MEA HVAC;
• MEA Electrical;
• MEA Fire;
• MEA Hydraulic;
• MEA Landscape;
• MEA Civil;
• etc.

Each Model Element Author is responsible for producing their part of the informational model, which must be produced based on the project specifications and the LOD required in relation to the various design phases.

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Organizational structure of a BIM project

What are the responsibilities of the MEA in BIM?

The main responsibilities of the Model Element Author (MEA) are:

• analyze the BEP (BIM Execution Plan) in which they will identify all the information about the informational model they must produce, including the level of detail (LOD – Level of Development) that must be achieved in the creation of their model;
• develop the model, or parts of it, for which they are responsible with a specific level of detail based on the particular design phase (concept design, preliminary design, developed design, detailed design, construction, operation);
• communicate any problems or inconsistencies to all project participants.

The MEA is not always responsible for the design of the element

In the BIM landscape, one of the most common misunderstandings relates to the overlap between the role of the person who concretely inserts an object into the digital model and the one who assumes its intellectual, technical, and legal authorship. The MEA is, by definition, the person tasked with defining, developing, and inserting a specific element within the model at a certain phase of the process.

However, this purely operational responsibility should not be confused with the technical and professional responsibility for the design. The MEA can act simply as a “digital executor,” translating into geometries and informational attributes the decisions made upstream by a structural engineer, an architect, or a mechanical engineer, without thereby signing off on the design of that element or validating its physical performance.

Difference between modeling and designing

To fully understand this dynamic, it is essential to draw a clear line between the act of modeling and that of designing. The designer is the licensed professional registered with their respective board who calculates, assesses overall performance, verifies compliance with regulations, and signs the documentation. They assume full civil and criminal responsibility for the physical behavior of the work, whether it involves the structural stability of a column or the thermal efficiency of a roofing package.

The modeler, on the other hand, deals with the graphic and informational transposition of these choices within the BIM authoring software. Although methodological evolution today requires modelers to have increasingly high technical and construction skills, the act of inputting data into the software does not shift ownership of the design choice, which remains firmly with the original designer.

The responsibilities of the MEA and the designer

Difference between Model Element Author and Model Element Owner

Delving deeper into data lifecycle management, it is useful to distinguish between the Model Element Author and the Model Element Owner (MEO). While the MEA represents the physical author or the party responsible for the generation and enrichment of information for a component at a specific stage of the project, the MEO is the “owner” or ultimate custodian of that element.

This transition is clearly reflected in the shift from the design and construction phase to Facility Management. A contractor or subcontractor may act as the MEA to input “As-Built” data related to a thermal power plant or an elevator system; once the work is completed and handed over, the client or asset manager becomes the Model Element Owner, inheriting the responsibility to maintain, update, and consult that information asset for long-term maintenance purposes.

What is the data lifecycle[/caption>

Difference between MEA, BIM Author, BIM Specialist and BIM Coordinator

It is often easy to confuse contractual acronyms with standardized professional roles. The MEA does not define a fixed profession or qualification, but rather a temporary and specific role assigned within a responsibility matrix of the model (the so-called Model Production and Delivery Table). In practice, the assignment of the MEA addresses the contractual question: “Who is responsible for inserting and developing this specific pillar or this specific piping at the established LOD?”.
On the other hand, the BIM Author and the BIM Specialist describe the operational professional profile that truly masters the software tools and models the objects for the various disciplines.
The BIM Coordinator, instead, operates at a higher level of management and control: they do not deal with the informational ownership or the modeling of the individual element, but supervise the overall quality, geometric consistency, and interdisciplinary coordination of the various models, ensuring that the work of different BIM Specialists converges into a single digital building organism free of interferences.

What is the MEA Schedule or Model Element Authoring Schedule?

The Model Element Author schedule – also called Model Element Table in the AIA Document G204-2022 – is a table that, based on the design specifications, assigns the modeling of the work elements to the various “authors” and defines the levels of detail to be reached (LOD – Level Of Development) for that specific part of the model and in relation to the various design phases.
The MEA Schedule serves to plan and clarify modeling roles, so it is important that it be prepared carefully and agreed upon among the various parties participating in the design process.
To accurately draft this table, it is necessary to have a clear understanding of the project, its modeling phases, the responsible professionals, and the various LODs to be reached.
The result of its careful compilation is an efficient modeling schedule that will lead to the production of a complete and multidisciplinary informational model that fully responds to the design specifications.
Below I provide you with an excerpt of a potential MEA Schedule in which you can appreciate the division based on the different elements to model (Model Element) to which a specific author and a specific LOD are assigned in relation to the project phase (Project Phase).

Model Element Author (MEA) in BIM

This is indeed an excerpt from a MEA schedule, the drafting of which would continue following the same programming methodology for the remaining model elements:

• site (Site);
• substructure (Substructure);
• structure (Structure);
• enclosure (Enclosure);
• interior partitions – horizontal and vertical (Interior);
• systems (Mechanical, Hydraulic, Electrical);
• fire protection system (Fire protection);
• etc.

Model Element Table: how it works

The Model Element Table (MET) represents the operational and contractual tool through which the information planning of a BIM project takes shape. It is a double-entry matrix that maps the entire building organism, breaking it down into individual elements or construction systems. The primary objective is to precisely establish who does what, when, and with what level of accuracy, eliminating ambiguities about modeling responsibilities during the project’s development.

As can be observed in the typical structure of this matrix, the operation is based on the intersection of strategic axes:

• Vertical axis – the list of model components is presented, generally structured according to standardized classification systems (such as UniFormat or OmniClass) to ensure unique nomenclature;
• Horizontal axis – the various phases of the project or delivery milestones (the so-called milestones, such as Concept Design, Preliminary Design, Developed Design) are placed.

At the intersection of each row and column, the two key parameters that govern the workflow are defined: the level of geometrical and informational development (LOD) that the object must reach at that precise moment, and the MEA (Model Element Author), which is the abbreviation for the subject entrusted with that enrichment. This structured scheme allows all the actors in the project to know how far they can legitimately rely on the information contained in the model at a given stage.

AIA G204-2022 and G205-2022

In the international context, and particularly in the United States led by the American Institute of Architects (AIA), the management of the Model Element Table has seen significant evolution with the publication of the 2022 suite of contractual and operational documents. The AIA has structured the flow of digital management by separating macro-strategic aspects from operational ones. In this scenario, the AIA G204-2022 and AIA G205-2022 modules are introduced, conceived as true independent working tools distributed in Excel format to provide maximum functionality to project teams.

Both documents share a similar internal organization, divided into tabs dedicated to legal management, the actual matrix, the list of authors’ abbreviations, and explanatory notes. The real difference lies in the level of detail and the project’s complexity:

• The G204-2022 (Model Element Table) adopts the complete CSI UniFormat™ classification, offering a deep and meticulous categorization, ideal for complex projects that require strict control of each individual building subsystem;
• The G205-2022 (Abbreviated Model Element Table) is an abbreviated and condensed version. It is designed for projects with a less intensive BIM implementation level or for teams that prefer a leaner and more macroscopic management of elements, without excessive fragmentation.

Difference between G204-2022 and old G202-2013

The transition from the old 2013 standard to the updated 2022 versions marks a profound paradigm shift in risk management and data ownership in BIM processes. In the previous framework, the reference document was the AIA G202-2013 (Building Information Modeling Protocol Exhibit). This standard was configured as a single all-encompassing protocol within which the element table was simply incorporated as a static section of the text.

The differences introduced with the G204-2022 compared to its predecessor move along three fundamental axes:

• Structural separation – in the current framework, strategic planning (collaboration protocols and the BIM Execution Plan managed in the G203-2022 module) is clearly separated from the operational tool. The G204 becomes an autonomous entity focused exclusively on mapping elements;
• Dynamicity of support – while the G202-2013 was a rigid contractual attachment in PDF, the G204-2022 is an interactive spreadsheet. This evolution allows participants to customize project phases, add or remove columns for intermediate milestones, and fill in the MEA fields through practical dropdown menus linked to the abbreviation tab.
• Focus on data reliability (Reliance) – the most recent documents have been rewritten with a central focus on limiting risks associated with model sharing. The G204 defines in much more stringent terms the level of authorized reliability for each element, protecting designers from improper or premature use of their data by third parties and facilitating the eventual inclusion of the model within contractual documents.

What are the other key roles in the BIM organizational structure?

The other key roles in the BIM organizational structure are:

• project BIM Manager;
• discipline BIM Lead.

The first figure, that of the Project BIM Manager, is responsible for achieving the project objectives related to various BIM Uses and the project information requests.

Among the responsibilities of the BIM Manager are:

• development of the BEP (BIM Execution Plan);
• updating the BEP;
• description of the various stakeholders;
• constant updating of the stakeholders in the BIM process;
• timely and efficient problem-solving;
• development of the informational model according to the requirements indicated in the BEP;
• coordination of model federation;
• assignment of roles and responsibilities for resolving hard clash and soft clash;
• supporting the client and project development to ensure compliance with BIM requirements and objectives.

Each discipline within a BIM project – architecture, structure, systems, etc. – should then have a BIM Lead to manage BIM activities related to that single discipline.

Among the responsibilities of the Discipline BIM Lead are:

• collaborating in the drafting of the BEP;
• participating in design review and model coordination meetings;
• facilitating the use of the BEP within the work team;
• ensuring that the model is produced according to what is indicated in the BEP;
• indicating and validating the various LOD in relation to various project phases;
• performing checks on the model before its sharing;
• communicating any issues to the Model Element Author;
• implementing internal coordination and clash detection and clash management procedures;
• managing model transfer and version control;
• managing BIM information in relation to the individual disciplines.

Within a BIM process, nothing is left to chance, and all figures involved, just like the Model Element Author, have clear roles and responsibilities.

Therefore, working by implementing BIM methodology is much more efficient than the traditional design approach. If you also want to verify the BIM advantages on your projects, you just need to try the BIM software most suitable for your discipline for free for 30 days.

FAQ about MEA (Model Element Author)

What is the Model Element Author in BIM?

The MEA, which stands for Model Element Author, is one of the key figures within a BIM Project alongside the ‘Project BIM Manager’ and the ‘Discipline BIM Lead’. It is the professional involved in the BIM process and is responsible for producing the informational model of the work or parts of it. The AIA Document G204–2022 defines it as the entity or individual responsible for managing and coordinating the development of a specific Model Element based on the required LOD in relation to the specific project milestone. Generally, the MEA disciplines are: MEA Architecture, MEA Structure, MEA HVAC, MEA Electrical, MEA Fire, MEA Hydraulic, MEA Landscape, MEA Civil, etc. Each MEA is responsible for producing its part of the model based on project specifications and the required LOD at various stages.

What are the responsibilities of the MEA in BIM?

The main responsibilities of the Model Element Author (MEA) are: 1) analyze the BEP (BIM Execution Plan) in which they will identify all the information regarding the informational model to be produced, including the level of detail (LOD) to be reached; 2) develop the model, or parts of it, for which they are responsible with a certain level of detail according to the specific design phase (concept design, preliminary design, developed design, detailed design, construction, operation); 3) communicate any issues or discrepancies to all project participants.

Is the MEA always responsible for the project of the element?

No. The MEA is the individual tasked with defining, developing, and inserting a specific element within the model at a certain phase, but this operational responsibility should not be confused with the technical and professional responsibility of design. The MEA can simply act as a ‘digital executor’, translating into geometries and informational attributes the decisions made upstream by a structural engineer, architect, or HVAC engineer, without thereby signing off on the design of that element or validating its physical performance.

What is the difference between who models and who designs?

The designer is the licensed professional registered with their relevant board who calculates, evaluates overall performance, verifies regulatory compliance, signs off on the documents, and assumes full civil and criminal responsibility for the physical behavior of the work. Those who model, on the other hand, are responsible for the graphic and informational transposition of these choices within BIM authoring software. The act of entering the data into the software does not transfer ownership of the design choice, which remains firmly with the original designer.

What is the difference between Model Element Author and Model Element Owner?

The MEA (Model Element Author) represents the physical author or the party responsible for the generation and informational enrichment of a component at a specific step of the contract. The MEO (Model Element Owner), on the other hand, is the ‘owner’ or ultimate custodian of that element. This transition is clearly manifested in the shift from the design and construction phase to Facility Management, where the client or asset manager inherits the responsibility of maintaining and consulting that informational asset for maintenance purposes in the long term.

What is the difference between MEA, BIM Author, BIM Specialist, and BIM Coordinator?

The MEA does not define a fixed profession but rather a temporary and specific role assigned within a matrix of responsibilities (Model Production and Delivery Table) to respond to the contractual question ‘Who models this element to the established LOD?’. In contrast, the BIM Author and the BIM Specialist describe the operational professional profile that actually masters the software and models the objects. The BIM Coordinator operates at a higher level: they do not deal with the modeling of the single element, but oversee the overall quality, geometric consistency, and interdisciplinary coordination of the various models.

What is the MEA Schedule or Model Element Authoring Schedule?

The Model Element Author schedule – also called Model Element Table in the AIA Document G204-2022 – is a table that, based on project specifications, assigns the modeling of work elements to various ‘authors’ and defines the levels of detail to be reached (LOD) for that specific part of the model in relation to the various project phases. It serves to schedule and clarify the modeling roles for all elements: site (Site), substructure (Substructure), structure (Structure), external envelope (Enclosure), internal partitions (Interior), systems (Mechanical, Hydraulic, Electrical), fire protection system (Fire protection), etc.

Model Element Table: how does it work?

The Model Element Table (MET) is a double-entry matrix. The vertical axis lists the components of the model, generally structured according to standardized classification systems (such as UniFormat or OmniClass). The horizontal axis contains the different phases of the project or delivery milestones. At the intersection of each row and column, the geometric and informational development level (LOD) and the MEA responsible for enrichment are defined. This allows all project actors to know to what extent they can rely on the information at a given phase.

What is the difference between the AIA G204-2022 and G205-2022 modules?

Both documents share a similar internal organization distributed in Excel format, but differ in the level of detail: G204-2022 (Model Element Table) adopts the complete CSI UniFormat™ classification, offering a deep and detailed categorization ideal for complex projects; G205-2022 (Abbreviated Model Element Table) is a shortened and condensed version, designed for projects with a lower level of BIM implementation or for teams that prefer a leaner management style.

What is the difference between G204-2022 and the old G202-2013?

The differences fall on three fronts: 1) Structural separation: in the current framework, strategic planning is clearly separated from the operational tool, making G204 an autonomous entity focused solely on mapping elements. 2) Support dynamism: the old G202-2013 was a rigid PDF attachment, while G204-2022 is an interactive Excel spreadsheet with drop-down menus. 3) Focus on data reliability (Reliance): G204 defines much more stringently the level of authorized reliability for each element, protecting designers from unpredictable or premature uses of their data.

What are the other key roles in the BIM organizational structure?

The other key roles are the Project BIM Manager and the Discipline BIM Lead. The Project BIM Manager is responsible for achieving project goals related to BIM Uses and information requirements (development/update of the BEP, coordination of the model federation, clash detection, etc.). The Discipline BIM Lead manages the BIM activities related to a single discipline (architecture, structure, systems, etc.) collaborating on the BEP, validating the LOD for their discipline, performing checks on the model before sharing, and communicating any problems to the Model Element Author.