What are LOD and LOIN and why we talk about them in BIM

BIM is a data-based working methodology. Too often, however, projects include information in excess or in limited quantities, which is why levels have been established to manage the correct amount of data, LOD and LOIN. Let's see what they are and what they are for.

WHAT IS LOD

The LOD is a concept introduced in BIM between 2004 and 2008, when it was integrated into the E202 Building Information Protocol Exhibit document thanks to the AIA , American Institute of Architects.

The LOD , an acronym for definition or development level, refers to the degree of completeness of the BIM models in the different phases of the project and is composed of a geometric and an information part: 

• LOG: Geometric attribute level, i.e. the visual representation of a project;
• LOI: Level of information, i.e. the data contained within the objects and the BIM model.

THE LOD IN ITALIAN LEGISLATION

In each country the LOD is structured differently depending on the regulations. In the United States, a numerical scale is used , ranging from LOD 100 , with basic geometric information, to LOD 500 , representing an As Build model.   

In the Italian UNI 11337 standard, an alphabetical system is used , which goes from LOD A to LOD G. In detail:

• A : Symbolic object , a CAD model equivalent to LOD 100;
• B : Generic object , where the geometric LOG represents the dimensions of the product and the LOI is clean and simple;
• C : Object defined , in which the LOG has greater definition and the information for the LOI increases (height, width, thickness, element name, type, etc.);
• D : Detailed object , in which the LOG has a value increasingly similar to the real product and the LOI increases the information with model, certifications, resistances and materials;
• E : Specific object , with more and more details including the manufacturer's name;
• F : Object executed , where you add details such as transmittance, installation date, maintenance, technical data sheets and weights. It is the equivalent of LOD 500;
• G : Object updated , indicates the update of the object compared to the As Build. The LOG and LOI are very detailed and integrate facility management.

FROM LOD TO LOIN

The ISO 19650 regulation abandons the concept of LOD to introduce the LOIN , i.e. the structured information content , information and data needed at a given moment. 

The LOIN is therefore not a precise standard, but it allows us to define the level of information needed in the model at a specific moment . It is divided into:

Part 1- Prerequisites, based on 4 questions: 

• Uses of information content;
• Information delivery times ;
• Who are the figures who request and provide the information;
• To which object is the information content related? 

Part 2 – Information needs, based on 3 key points: 

• What geometric representation do you want to give to the object;
• What is the alphanumeric information , i.e. the list of properties; 
• The set of documents linked to the object.

WHY CHOOSE LOIN 

If previously we talked about LOD with LOG and LOI and there wasn't a clear definition, with the LOIN we go directly to the project and can actually understand what the needs are and why the work is being carried out.

In this way it is possible to more easily obtain the fundamental information to be inserted at a geometric, alphanumeric and documentation level within the model.

Would you like to know more? You can find all the information about LOD and LOIN in our BIMeet podcast !