BIM academy · L4 Practitioner · 18 hours
Coordinate trades and take off quantities (LOD 300)
Bring architecture, structure and services together, find clashes and produce quantities you can defend.
task, condition, standard
What you will be able to do
- Task. Coordinate three models of a two-storey campus, resolve clashes and produce a quantity list at LOD 300.
- Condition. Three discipline models (architecture, structure, services), our element library and a clash rule list.
- Standard. All hard clashes closed, soft clashes noted, and quantities within 3 per cent of a hand check.
four modules
Modules, with worked examples
Module 1: Link models and agree an origin (4 h; Apply)
- All models share one origin and one set of levels.
- Link, do not copy.
- Record the model versions used in each check.
Worked example. If the services model is 2 m off, every pipe appears to hit a wall.
Activity. Link three models and confirm they align.
Standard. Alignment checked at three points.
Module 2: Find and sort clashes (5 h; Analyse)
- A hard clash is two things in one place. A soft clash is a clearance not kept.
- Rank clashes: safety first, then function, then comfort.
- Assign each clash to one owner.
Worked example. A duct crossing a stair headroom is a safety clash and is fixed first.
Activity. Run a clash test and rank the first ten.
Standard. Ten clashes ranked with owners.
Module 3: Raise detail to LOD 300 (4 h; Apply)
- Add exact sizes, materials and fire ratings.
- Keep supplier names out. Use performance text.
- Check that each element still has its code.
Worked example. A partition CS-IN-01 now states a fire rating and an acoustic rating, but no brand.
Activity. Apply LOD 300 to one room.
Standard. Ratings present and no brand names.
Module 4: Take off quantities (5 h; Evaluate)
- Quantities come from the model.
- Compare one quantity by hand to test the model.
- State the allowance for waste clearly.
Worked example. Wall area from the model is 100 m2. Hand check gives 102 m2. That is within 3 per cent.
Activity. Produce a list for the interior and check three items.
Standard. Three items within 3 per cent.
five checks
Check yourself
Think of your answer first, then open the question.
Q1. What is the difference between a hard and a soft clash?
Model answer. A hard clash is two objects in one place. A soft clash is a required clearance that is not kept.
Q2. Which clashes are fixed first?
Model answer. Safety ones, then function, then comfort.
Q3. Why link models instead of copying them?
Model answer. So everyone sees the latest version and nothing drifts.
Q4. What must be absent from LOD 300 text?
Model answer. Supplier and maker names.
Q5. How do you test a model quantity?
Model answer. Compare it with a hand calculation and accept a small, stated difference.
where this takes you
Jobs this supports
- BIM coordinator. Runs clash checks and keeps models aligned.
- Quantity surveyor technician. Produces quantity lists from models.
ladder L1 to L7
The seven levels
Step in at your level and move up. Credits stack.
- L1 Basic: Buildings and models: the basics
- L2 Awareness: BIM awareness: read a model and a standard
- L3 Foundation: Model a campus module to LOD 200
- L4 Practitioner: Coordinate trades and take off quantities (LOD 300) (you are here)
- L5 Specialist: Fabrication models, programme and cost (LOD 350 to 400)
- L6 Advanced: Lead a BIM project: plans, rules and audits
- L7 Super expert: Campus network standards and digital twins
Learning material, not a design or safety instruction. Real buildings are designed and signed off by licensed professionals under local rules.