If you already do this for a living: Ownership changes between stages. The matrix should show where an element passes from one discipline to another, such as a curtain wall going from architect to specialist.
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The matrix copied from the last project has 400 rows and no owners. At the stage gate nobody can say whether the targets were met, because nobody knew which rows were theirs.
The team cuts the list to 45 elements, sets stage 4 targets first, and names an owner for every cell. At the gate each discipline reviews its own rows in ten minutes, and the matrix becomes the source of the project’s IDS checks.
Many LOD matrices are long spreadsheets that someone wrote once and nobody reads again. Here is how to write one people will actually use.
1. Start from a list, then cut
Begin with a standard list of elements — walls, slabs, ducts, cable trays and so on — and remove what your project does not need. A matrix with 40 meaningful rows is far more useful than one with 400. Group rows by discipline or category so each team can find its own elements quickly.
Add a classification code (for example Uniclass or OmniClass) if the project uses one. It helps link the matrix to model properties and to cost data.
2. Set targets where they matter
Do not fill every cell at once. Start with the stage where spatial coordination happens — that is where element reliability matters most for clash detection. Set those targets first, then work backwards (what is enough earlier?) and forwards (what is needed for construction and handover?).
Use a dash for “not required”. An empty cell is ambiguous; a dash is a decision.
3. Give every target an owner
Each non-empty cell needs a responsible discipline. Sometimes ownership changes between stages: the architect may own a curtain wall at concept design, while a specialist contractor develops it to fabrication level. Make that handover visible in the matrix.
4. Say what information is required
LOD describes geometry and reliability, not data. For elements where data matters — doors, plant, fire-rated walls — list the required attributes: fire rating, manufacturer, model number, maintenance interval. These lists become the basis for automated model checks, for example with an IDS file.
5. Review at every stage gate
Bring the matrix to the stage gate review. Check that elements meet their targets, update targets if the scope or procurement route has changed, and issue a new revision. Keep the revision history so everyone can see what changed and when.
Key takeaways
- Start from a standard element list and remove what the project does not need.
- Set targets per stage, starting at the milestone that matters most (often spatial coordination).
- Every non-empty cell needs a responsible discipline.
- List the required attributes for elements where data matters, and review the matrix at each stage gate.
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Related tool
Set the level of development per element and stage, with responsibilities and information requirements.
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