BIM

LOD 400 (Fabrication / Construction)

Element accurate for fabrication, assembly, detailing. Includes connection details, manufacturer data.

Also calledlod 400level of development 400
Related on InfraLens
CODES
ISO 19650
Definition

LOD 400 (Level of Development 400) is the BIM Forum specification level representing 'Fabrication / Construction'. Model elements have manufacturer-specific information, complete connection details, fabrication-ready data, and accuracy suitable for direct fabrication or construction. Per BIM Forum LOD Specification + ISO 19650, LOD 400 is the typical level for shop drawings of structural steel, pre-cast concrete, MEP equipment, and curtain walls.

LOD 400 element examples: (a) Structural steel beam — exact dimensions, manufacturer-specific section, connection details with bolt patterns and welding, fabrication-ready geometry. (b) Pre-cast concrete element — manufacturer-specific connections, lifting points, embedded reinforcement details. (c) MEP equipment — manufacturer-specific model, exact dimensions, connection points with utilities. (d) Curtain wall — fabrication-ready frame and glazing, weather-resistance details. The model is suitable for direct fabrication; quantities are exact; cost estimation is ±2-5% accuracy.

Indian projects typically achieve LOD 400 for: (1) Pre-engineered building (PEB) primary members — fabrication shop drawings. (2) Pre-cast concrete elements — sleepers, beams, panels. (3) Structural steel for major commercial — fabrication drawings. (4) MEP for major commercial — manufacturer-specific equipment models. (5) Curtain walls and façade elements. Below LOD 400: specifications and geometries not suitable for direct fabrication. Above LOD 400 (i.e., LOD 500): field-verified as-built information for facility management.

Where used
  • Pre-engineered building (PEB) primary structural fabrication
  • Pre-cast concrete element fabrication
  • Structural steel shop drawings for major commercial
  • MEP equipment with manufacturer-specific data
  • Curtain walls and façade elements
Acceptance / threshold
Per BIM Forum LOD Specification + ISO 19650 + project BEP: manufacturer-specific information; complete connection details; fabrication-ready data; verified during shop drawing review.
Frequently asked
What is LOD 400?
LOD 400 (Level of Development 400) is the BIM Forum level representing fabrication / construction. Manufacturer-specific information, complete connection details, fabrication-ready data. Suitable for direct fabrication or construction. Used for: PEB structural members, pre-cast concrete, structural steel shop drawings, MEP equipment, curtain walls.
What is the difference between LOD 350 and LOD 400?
LOD 350 (construction documentation): fabrication-ready details for elements with coordination challenges (façade, complex MEP). LOD 400 (fabrication): manufacturer-specific information, complete connection details, fabrication-ready data. LOD 400 is more specific (manufacturer-specific) than LOD 350. Modeling time for LOD 400 is 30-40% more than LOD 350.
Is LOD 400 needed for all elements?
No — LOD 400 is needed only for elements actually being fabricated by manufacturer-specific information. For pre-engineered building primary members: yes, LOD 400 for shop drawings. For pre-cast concrete: yes. For routine cast-in-situ elements: LOD 350 sufficient. Major Indian projects achieve LOD 400 for fabrication-relevant elements; LOD 350 for in-situ cast.
Related bim terms
Building Information Modelling (BIM)
ISO 19650 information management with BIM. India has no published IS BIM standard — projects reference ISO directly.
ISO 19650 Series
5-part international standard for BIM information management. Parts 1-5: concepts, delivery, operations, exchange, security.
Industry Foundation Classes (IFC)
Open ISO standard file format for BIM exchange. IFC 4.3 ADD2 supports buildings + infrastructure.
Level of Development (LOD) / LOIN
AIA LOD 100-500 vs BIMForum LOD Spec vs ISO 7817-1 LOIN. Defines geometric/info detail per object per milestone.
Common Data Environment (CDE)
Single trusted location for all project information. Mandatory under ISO 19650 with WIP→Shared→Published→Archived states.
BEP & EIR — BIM Execution Plan / Exchange Information Requirements
EIR = client requirements (in tender). BEP = how the contractor will deliver them. MIDP/TIDP = the schedule.
Uniclass / OmniClass / Classification
Uniclass 2015 (UK) is the most-used BIM classification on Indian projects. India has no published classification.
BIM Roles — Manager, Coordinator, Modeller
BIM Manager (firm), Project BIM Manager (one project), Information Manager (enforces ISO 19650), BIM Coordinator (clash), Modeller (authoring).