Understanding model element development requirements at each project stage for BIM coordination and delivery
Level of Development (LOD) defines the degree to which the geometry and associated information of a BIM element has been developed. It establishes a common language between project stakeholders about what level of detail and reliability can be expected from model elements at different project phases. LOD is not just about geometry - it includes the associated data, specifications, and documentation.
Level of Development (LOD) refers to the overall maturity of a model element. Level of Detail (also LOD) refers only to graphic appearance. Level of Information (LOI) refers to non-graphic data. Some frameworks use LOD to encompass both detail and information, while others separate them. This guide follows the BIMForum LOD Specification approach.
Overall building massing, indicative area, height, volume, location, and orientation
Shown as single lines or simple planes. No material layers defined. Approximate locations based on space planning.
May be indicated by symbols only, or as simple voids. No specific sizes, types, or schedules.
Building footprint and approximate height. Structural system type may be noted but not modeled.
Major plant spaces identified. No equipment or distribution modeled. Allowances for risers and plantrooms.
Elements modeled as generic systems or assemblies with approximate quantities, size, shape, location
Generic wall types with approximate thickness. Exterior vs interior differentiated. No specific material layers or components.
Generic types placed with approximate sizes (e.g., "single door 900mm"). No hardware, frame details, or specific product selections.
Structural grid established. Column and beam locations approximate. Slab zones indicated. Member sizes not finalised.
Major equipment sized and located approximately. Main distribution routes indicated. Placeholder spaces for coordination.
Elements modeled as specific systems with accurate quantity, size, shape, location, and orientation
Specific wall types with defined layers and materials. Accurate dimensions. Fire ratings assigned. Quantities extractable for takeoff.
Specific types, sizes, and configurations selected. Schedule data complete. Frame types defined. Hardware groups assigned.
Designed member sizes and materials. Connection types indicated. Reinforcement schedules for concrete. Steel connections shown conceptually.
Equipment make and model identified. Duct and pipe sizes determined. Routing complete. Loads and capacities assigned.
Elements modeled with detail for coordination between disciplines and trades
All LOD 300 plus: cavity closers, lintels at openings, movement joints, penetration sleeves, fire stopping locations.
All LOD 300 plus: frame profiles, threshold details, weather seals, structural supports for openings.
All LOD 300 plus: cast-in items, embed plates, penetrations, interface with cladding supports, edge conditions.
All LOD 300 plus: hangers and supports, access panels, coordination sleeves, insulation, clearance zones.
Elements modeled with sufficient detail and accuracy for fabrication and assembly
Exact member profiles, connection plates, bolt holes, welds, camber, coatings. Model ready for CNC fabrication.
Panel geometry, edge profiles, reveals, embedded items, lifting inserts, reinforcement, mix specifications.
Manufacturer-specific models with exact dimensions, connection points, service clearances, weight, electrical requirements.
Exact mullion profiles, glass types by panel, bracket locations, thermal breaks, gaskets, panel fabrication details.
Elements verified as constructed and ready for facilities management
Field-verified locations matched to as-built survey. Deviations from design documented. Point cloud comparisons.
Installed product details: manufacturer, model, serial numbers, warranty information, installation dates.
Maintenance schedules, spare parts lists, supplier contacts, operating manuals linked or embedded.
Test results, commissioning certificates, performance verification, balancing reports for MEP systems.
| Element | LOD 100 | LOD 200 | LOD 300 | LOD 350 | LOD 400 |
|---|---|---|---|---|---|
| Wall | Single line | Generic thickness | Specific type & layers | + openings, supports | Shop-ready panels |
| Door | Symbol only | Generic size | Type, hardware group | + frame, threshold | Manufacturer model |
| Column | Grid intersection | Generic shape | Sized member | + connections, embeds | Fabrication model |
| Duct | Zone allocation | Approximate route | Sized and routed | + supports, access | Fabrication spools |
| Light Fixture | Lighting zones | Generic symbol | Specified type | + mounting, power | Exact product model |