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Exchange Information Requirements (EIR), define what information a client needs in a BIM project:
- when it is required,
- what it will be used for and
- the quality it must meet.
They provide a binding framework for BIM information management, information deliverables, BIM use cases and the subsequent BIM Execution Plan (BEP; German: BIM-Abwicklungsplan or BAP).
Why are exchange information requirements important?
- Clear requirements: Contractors know at an early stage which models, data and documents are required.
- Fit-for-purpose information: Only the information genuinely needed for the relevant BIM use cases is requested.
- Reliable data quality: Requirements relating to content, level of detail, formats and delivery dates are clearly defined.
- Better collaboration: Consistent specifications reduce misunderstandings between the client, design teams and contractors.
- Basis for the BEP: The BIM Execution Plan subsequently specifies how the requirements will be implemented in practice.
What do exchange information requirements include?
Their precise structure depends on the project and the client’s BIM objectives. Typical components include:
BIM objectives
The first step is to define the benefits that BIM should provide for the project.
Possible objectives include:
- greater planning certainty
- better coordination between specialist disciplines
- transparent quantities and costs
- support for refurbishment and conversion projects
- structured documentation of existing buildings
- digital handover of data for building operations
BIM use cases
The EIR specify the tasks for which BIM will be used. These use cases should be derived from the BIM objectives and contribute to achieving them.
Typical use cases include:
- existing-building capture
- as-is modelling
- Scan-to-BIM
- model coordination
- clash detection
- drawing production
- quantity take-off and cost estimation
- construction progress monitoring
- as-built documentation
- handover of building data for operations
Different information requirements may apply to each use case.
Digital deliverables
The EIR define which digital outputs must be delivered at specific stages of the project. These deliverables are the results produced by the various use cases at different points in the project.
Examples include:
- BIM models
- as-is models
- IFC files
- point clouds
- floor plans, sections and elevations
- audit reports
- model-checking results
- as-built models
- documentation
The delivery date, data format and intended purpose are generally specified as well.
Model and data requirements
Requirements for structure and content must be defined so that digital information can be used reliably.
These may include:
- model structure
- building element classification
- attributes and property sets
- coordinate systems
- units
- file-naming conventions
- exchange formats
- geometric requirements
- alphanumeric information
EIR and level of information need (LOIN)
The Level of Information Need (LOIN) is a central element of the EIR.
LOIN describes what information is genuinely required for a specific purpose. It is not about adding as much detail as possible to every model.
Instead, the following is defined for the specific project:
- what geometric information is required
- what alphanumeric information is needed
- what documentation is necessary
- when this information must be available
- which use case requires the information
This prevents models from becoming excessively detailed while also ensuring that they contain sufficient information for their intended purpose.
How are exchange information requirements developed?
1. Define the BIM Objectives
The client defines the specific benefits that BIM should provide for the project.
2. Select the BIM Use Cases
Specific use cases are derived from these objectives, such as existing-building capture, coordination or building documentation.
3. Determine the Information Needs
The information genuinely required for each use case is defined.
4. Define Deliverables and Delivery Dates
The client determines which models, documents or data must be provided and when.
5. Establish Quality Requirements
Formats, model content, LOIN, checking processes and other requirements are documented.
6. Create the Basis for the BEP
Once the contract has been awarded, the BIM Execution Plan describes how the requirements set out in the EIR will be implemented from a technical and organisational perspective.
EIR for existing-building digitisation and scan-to-BIM
Precise information requirements are particularly important for existing-building projects. Before the building survey begins, it should be clear which data is genuinely needed for design, refurbishment or operation.
The EIR may define:
- which areas of the building must be captured
- what geometric accuracy is required
- which building elements must be included in the as-is model
- what LOIN is required
- which attributes are needed
- which coordinate system must be used
- which output formats must be delivered
- whether point clouds must be provided in addition to the BIM model
- which data is relevant to subsequent building operations
The information requirements therefore influence the method and scope of existing-building capture from the outset.
One possible information flow is:
EIR → digital building survey → point cloud → Scan-to-BIM → IFC model → CDE → design and operation
The more precisely the subsequent information needs are defined, the more purposefully buildings can be captured and digital as-is models created.
EIR vs. BIM Execution Plan (BEP)
The EIR and BEP are closely connected, but they serve different purposes.
Exchange Information Requirements (EIR)
- are formulated from the client’s perspective
- define the required information and BIM services
- establish BIM objectives and use cases
- specify requirements for information deliverables
- provide a basis for tendering and contract award
- describes the practical implementation
- is prepared and agreed by the contractor team
- defines processes and responsibilities
- describes data exchange and collaboration
- specifies checking, coordination and approval processes
In simple terms:
- EIR = What is required? Comparable to a client requirements specification.
- BEP = How will it be implemented? Comparable to an implementation specification.
EIR vs. Level of information need (LOIN)
EIR
- EIR and LOIN are not the same.
- The EIR provide the overarching framework for a project’s information requirements.
LOIN
- Within this framework, LOIN specifies the extent of information genuinely required for a particular purpose and point in time.
- LOIN is therefore a tool for describing the requirements defined in the EIR more precisely.
EIR and the common data environment (cde)
The EIR may also define requirements for the Common Data Environment.
These may include:
- use of the CDE
- access and permission concepts
- data and file structures
- information status
- exchange and approval processes
- archiving
- data protection and data security requirements
If a BIM collaboration platform is used for model-based coordination, these requirements may also cover how the platform is used.
The BEP subsequently specifies how these requirements will be implemented in the project.
Common mistakes and misconceptions
- Adopting an EIR template without modification: Templates provide guidance, but they must be adapted to the project, its BIM objectives and its use cases.
- Requesting too much information: More model information does not automatically provide more value. Information needs should be based on the relevant use case.
- Confusing the EIR with the BEP: The EIR define the client’s requirements, while the BEP describes how the contractor will implement them.
- Unclear delivery dates: Information is only useful if it is available at the right time.
- Failing to specify existing-building data sufficiently: Accuracy, scope and required model information must be defined early in Scan-to-BIM projects.
- Defining file formats only: Technical formats alone are no substitute for clearly defined information requirements.
- Overlooking the operational phase: If the model will subsequently be used in CAFM or building operations, the relevant information must be considered at an early stage.
FAQ
Who creates the EIR?
The EIR are created by the client or under the client’s responsibility.
When are the EIR created?
The EIR should be defined before tendering or contract award because they describe the requirements for the BIM services and information deliverables to be provided subsequently.