What is Level of Information Need (LOIN) and Why it Replaced LOD

Building Information Modeling (BIM) has revolutionized the Architecture, Engineering, and Construction (AEC) industry, but with a wealth of digital data comes a critical challenge: managing what information is needed, when, and by whom. For years, the industry relied on the concept of Level of Development (LOD) to manage this. However, a new, more robust framework, the Level of Information Need (LOIN), has emerged, officially replacing LOD as the central concept in the international ISO 19650 standard. This shift isn’t just about changing an acronym; it’s a strategic evolution that puts purpose and clarity at the heart of information management.

The Ambiguity of LOD: Why the Industry Needed a Change:-

The term LOD, which has been interpreted to mean Level of Detail, Level of Definition, or Level of Development, served as an early, essential benchmark in BIM. It structured the progressive completeness of a model element, typically on a scale from LOD 100 (conceptual) to LOD 500 (as-built). LOD was intended to define the clarity and usability of BIM data.

However, LOD suffered from several key drawbacks:

Vague Interpretation: The lack of a single, universally accepted definition led to confusion, especially in cross-border projects where a US team’s LOD 300 might mean something different from a UK team’s expectation. This was compounded by inconsistent interpretations across the industry.
Focus on Geometry: LOD primarily centered on the geometric completeness the shape, size, and location of the model element—often overlooking the crucial non-geometric information (attributes, data, specifications) and necessary documentation. It was largely designed for model-based work.
The Problem of Over-Modelling: Because contracts often vaguely requested “high LOD,” professionals tended to exaggerate the amount of information to be communicated to avoid deficiencies. This resulted in producing excessive, unnecessary information far earlier than needed, leading to unnecessary work, larger file sizes, and wasted resources. This wasn’t about the need for the information, but the level of the model itself.

This ambiguity highlighted a core problem: the focus was on the object’s characteristics, not the purpose for which the information was required.

For further reading on essential BIM foundations, check out: BIM for Beginners: A Guide to Getting Started in Building Information Modeling

Introducing LOIN: A Purpose-Driven Approach to Information Need:-

The Level of Information Need (LOIN), introduced by the BS EN ISO 19650 series, fundamentally shifts the perspective. It moves the focus from what can be modelled to what information is strictly required to fulfill a specific task or purpose at a particular project milestone. The shift is strategic, asking project teams to stop modeling for the sake of it and start modeling with intent.

LOIN ensures that all parties know exactly:

Why the information is needed (the purpose)
When it’s needed (the deadline or project stage)
Who requires it (the responsible “Actor” or stakeholder)
What is required (the information content itself, including geometry, information, and documentation)

This purpose-driven approach is key to streamlined workflows, preventing “information wastage,” and aligning all project deliverables with tangible goals. It provides a clearer framework for defining information requirements.

The Three Pillars of LOIN:-

LOIN clarifies requirements by encompassing three specific types of information:

Geometric Information: Defines the graphical representation, covering:
- Detail: How detailed the information needs to be.
- Dimensionality: Whether 2D, 3D, or simply a 0D point/1D line.
- Location & Appearance: How the location is defined and the required visual appearance.
- Parametric Behavior: If the data needs its own intelligence for manipulation and dynamic changes.
Alphanumeric Information: The non-geometric data attached to the model element, such as:
- How the information is to be uniquely identified.
- What is the correct amount of information content required (metadata).
- Material specifications, manufacturer warranties, and energy efficiency data.
Documentation: Crucial unstructured data that supports the model, including:
- Reports and specifications.
- Manuals, photographs, sketches, and handovers.
- The inclusion of documents recognizes that unstructured data remains an important output of projects.

By breaking down the need this way, LOIN provides the necessary granularity to request only what is essential for the task at hand.

LOIN’s Strategic Advantage: From Complexity to Clarity:-

The transition to the LOIN framework is an industry-wide commitment to smarter, more efficient project delivery. It directly addresses the common challenges faced in projects, especially when dealing with advanced concepts like Digital Twins or asset management.

For example, a Facility Manager requires an LOIN that prioritizes rich, accurate alphanumeric data about an HVAC unit’s warranty, serial number, and maintenance schedule, rather than an overly complex geometric model (high LOD) that only slows down their system. This process of tailoring information delivery to specific needs enhances collaboration and reduces errors.

LOIN allows for flexible, purpose-driven specification, ensuring the right information is delivered to the right people at the right time. This is critical for improving efficiency, reducing errors, and leading to better project outcomes.

The LOIN Advantage in Action:

Risk Reduction: By clarifying requirements, LOIN minimizes miscommunication, reduces the risk of errors, and ensures project deliverables align with the contract.
Asset Management: For the operational phase (post-construction), the focus shifts heavily to alphanumeric data, such as maintenance history and replacement schedules. LOIN ensures this data is clearly defined and delivered for long-term use.
Streamlined Collaboration: LOIN fosters collaboration among project stakeholders by ensuring everyone works with a common, unambiguous understanding of data requirements.

LOIN elevates BIM from a 3D modeling exercise to a true information management process. By focusing on the need rather than the level, it enables all stakeholders from architects and engineers to contractors and facility managers—to collaborate effectively and reduce the risks of errors, rework, and cost overruns. It is the definitive modern standard for building a future-ready construction technology ecosystem.

To see the long-term application of this data, read: The Revolutionary Impact of Digital Twins on Facility Management and Operations

The Future of LOIN: A Crucial Skill in AEC:-

For anyone involved in a project, understanding the principles of LOIN is no longer optional it is a mandatory skill. It’s the framework that supports informed decision-making throughout the project lifecycle. As the industry continues to move toward standardization with ISO 19650, the clarity provided by LOIN will only become more essential for successful project delivery.

If you’re looking to advance your career, learn more here: Why BIM is a Crucial Skill for a Future-Ready Career in AEC

The shift from LOD to the Level of Information Need is not just semantic; it’s a strategic choice to make information purposeful, specific, and valuable to every single member of the project team.

Learn how this clear information flow transforms professional services: How BIM (Building Information Modeling) is Transforming Consultancy

FAQ’s:-

Q1: Is LOIN completely replacing LOD in all project contexts?
A. The ISO 19650 series, the international standard for information management using BIM, has adopted LOIN as the primary framework, moving away from the ambiguities of LOD. While many organizations still reference LOD, they are increasingly defining it through the lens of LOIN’s clear, purpose-driven requirements for geometry, data, and documentation.

Q2: What are the key components of a LOIN specification?
A. A full LOIN specification addresses three main components: Geometric Information (detail, dimensionality, location), Alphanumeric Information (non-graphic data like attributes and specifications), and Documentation (reports, manuals, etc.). It also clarifies the Purpose, Actor (Who), and Timing (When) of the information exchange.

Q3: How does LOIN help in reducing project costs?
A. LOIN reduces costs by preventing over-modelling and information waste. By precisely defining the necessary level of information—and only that information for each stage, project teams avoid spending time and resources generating unnecessary geometric detail or populating irrelevant data fields.

Q4: Is LOIN just for architects and engineers?
A. Absolutely not. The framework is designed to serve all project stakeholders. An engineer might use LOIN to specify structural component data, a contractor to specify fabrication details, and a facility manager to specify asset maintenance information. It ensures every “Actor” gets the right information tailored to their specific need.

Q5: Where can I find the official definition of LOIN?
A. The formal definition of Level of Information Need (LOIN) is established in the international standard for information management in the AEC industry, specifically the BS EN ISO 19650 series (often referenced with BS EN 17412-1).