All articles
BIM Basics
What is LOD?
Level of Development tells you how much you are allowed to trust a model element. Agreeing it up front prevents most delivery disputes.
5 min read
The levels
- LOD 100 — conceptual mass; area and volume only.
- LOD 200 — generic elements with approximate size and location.
- LOD 300 — accurate size, shape and position; suitable for construction documents.
- LOD 350 — LOD 300 plus modelled interfaces between systems and supports.
- LOD 400 — fabrication and assembly detail, including connections and rebar.
- LOD 500 — verified as-built condition.
What changes with each level
- Geometry accuracy
- Attached data (grade, material, model number)
- How reliable a quantity take-off from the model is
- How much coordination has been performed
How to use it in a contract
- State the LOD per discipline, not for the project as a whole.
- List the deliverable formats at each milestone.
- Say explicitly whether quantities are contractual or indicative.
- Fix who owns coordination and how clashes are signed off.
Have a project question?
Send your drawings or plot details and we will tell you plainly what BIM would change for your project.