# Italian LOD (UNI 11337) vs international LOD 100–500 and ISO 19650 LOIN: how they map > How to compare UNI 11337-4 LOD A to G with the LOD 100-500 scale and with the ISO 19650 level of information need. A mapping table and its limits. Published 2026-11-06 Italy's UNI 11337-4 LOD A to G and the LOD 100-500 scale common in the United States describe the same idea, how developed a model object is, but they do not line up step by step. ISO 19650 uses neither scale: it asks for a level of information need defined for each purpose, milestone and object. A mapping between the three exists, but it is approximate and contracts should say so. Working on Italian and international contracts, we often have to translate requirements written in one scale for a design team that thinks in another. This article sets out the table we use as a starting point and the limits to keep in mind. ## Three systems, three logics UNI 11337-4 (Italy). It defines seven levels of development for digital objects, LOD A to LOD G, and separates the geometric component (LOG) from the information component (LOI). The last two levels, F and G, cover the executed asset and its service life. LOD 100-500 (United States). The BIMForum specification, derived from the AIA protocol, uses levels 100, 200, 300, 350 and 400. LOD 500, the field-verified element, is defined in the AIA protocol but not detailed in the BIMForum specification. LOD measures how far others can rely on an element, not how good the model looks. Level of information need (ISO 19650, EN ISO 7817-1). ISO 19650 asks information requirements to state the level of information need. EN ISO 7817-1, which replaced EN 17412-1, explains how to define it: for each purpose, milestone, actor and object you specify geometrical information (detail, dimensionality, location, appearance, parametric behaviour), alphanumerical information (identification and content) and documentation. It is a method, not a scale. Annex I.9 of Italy's Public Contracts Code uses the phrase "levels of information need" among the minimum contents of the capitolato informativo, the Italian EIR. In practice Italian requirements often combine ISO vocabulary with UNI 11337-4 classes. ## The mapping table The table below is our starting point for translating requirements between systems. The mapping is approximate: no standard sets it officially, and the content required for the same level changes by element category and by specification. UNI 11337-4 What it describes US LOD (approx.) How to write it as a level of information need LOD A, symbolic object Symbol or generic representation, indicative characteristics LOD 100 Geometry: 2D symbol or indicative volume. Data: element type. Documents: none LOD B, generic object Generic or envelope geometry, indicative characteristics LOD 200 Geometry: envelope with approximate dimensions. Data: function and expected performance LOD C, defined object Defined geometry, characteristics of a family of similar products LOD 300 Geometry: defined size and position. Data: performance and code requirements LOD D, detailed object Detailed geometry, interfaces with other systems, approximate maintenance clearances LOD 350 (sometimes 400) Geometry: detail with connections and clearances. Data: characteristics of a defined range of products LOD E, specific object Specific product, fabrication, assembly and installation detail LOD 400 Geometry: shape of the chosen product. Data: manufacturer, model. Documents: datasheets, shop drawings LOD F, executed object Object installed and verified on site, with maintenance information LOD 500 Geometry: as-built with stated tolerance. Data: asset codes, serial numbers. Documents: certificates, manuals LOD G, updated object Object condition over time: maintenance, replacements, decay No direct equivalent Data: intervention history and condition, updated in operation under ISO 19650-3 Three warnings about the table. - LOD D is the least certain step. Some map it to LOD 350, others to 400. It depends on how much construction detail the requirements ask for. - US LOD 500 is about field verification, not operation. The maintenance part of Italian LOD F has to be requested explicitly. - LOD G has no counterpart in the US scale. In international contracts it is better expressed as a requirement to keep the asset information model, the AIM of ISO 19650-3, up to date. ## Where the mapping breaks down Same number, different objects. LOD 300 for a wall and LOD 300 for an air handling unit do not ask for the same information. That is why both BIMForum and UNI 11337-4 describe levels per element category. Geometry and information travel separately. UNI 11337-4 separates LOG and LOI. Clients often need simple geometry and a lot of data, for facility management for example, and a single label cannot express that. Levels are not phases. Under Legislative Decree 36/2023 Italy has two design stages, the technical and economic feasibility project and the detailed design. Linking a LOD to each stage is a useful guide, but one model holds objects at different levels. Surveys of existing assets follow their own rules. In Scan to BIM the tolerance against the point cloud matters more than the label. We explain this in our Scan to BIM guide, including why at Villa Serena we worked with tolerances per element category. ## How we write it into contracts Our method is the same whether we draft requirements for a client or respond to them. - Start from model uses. Quantity take-off, clash coordination, facility management: each use needs different information. - Build a matrix per element category and per stage, with the three columns of the level of information need: geometry, data, documents. - Use the label as a summary. A UNI 11337-4 LOD column, plus the matching LOD 100-500 if needed, helps readers, but the matrix is what binds. - Make the matrix checkable. Required properties can be written as IDS rules and checked automatically on IFC files. This is the work of our BIM validation service. On the Roma Tre University Rectorate, working for Manens-Tifs, BIMON developed the final and detailed design of the electrical, special and mechanical systems and the multidisciplinary BIM coordination, extracting the drawings for both stages from the model. It is the typical case of one model growing in level: MEP systems become more detailed from stage to stage, while other elements stay where they are because nothing more is needed. On Doha's Red Line North BIMON supported Italferr in the BIM coordination of seven underground stations, with final and detailed design drawings extracted from the federated model. When several teams produce models in parallel, a shared definition of development level per category stops each station from reading the requirement its own way. ## Summary - The A-G to 100-500 mapping helps you find your way, not sign a contract. - The ISO 19650 level of information need is the reference method, in Italy too. - The document that matters is the matrix by category, stage and use, attached to the information requirements. Definitions of LOD and LOIN are in our glossary. For the full standards framework see ISO 19650 and UNI 11337 in practice. If you need to write or read a requirements matrix, our BIM management team can set it up with you.