Designing with the model
What does a designer's model need, so everyone after them can use it?
The design model is what estimators, planners, checkers, contractors and facilities teams all build on. Model to the information they need, export IFC they can use, check your own work before it's shared, and keep the drawings in step.
Understand
What it is, in plain language
- Pedia · StandardsLOD vs LOINHow the Level of Development scale differs from ISO’s level of information need, and why ISO 19650 projects describe geometry, data and documents separately.
- Pedia · SoftwareIFC (Industry Foundation Classes)The open, vendor-neutral data format and schema for exchanging building and infrastructure models between software.
- Pedia · SoftwareProperty sets (Psets) and quantity setsHow IFC groups element information into named sets of properties and quantities, the standard Pset_ and Qto_ sets, and custom sets.
- Pedia · StandardsIDS (Information Delivery Specification)A buildingSMART standard for writing information requirements as machine-readable rules, so IFC models can be checked automatically.
- Pedia · WorkflowsModel checkingChecking a model against rules before it is shared or accepted — information, naming, geometry, structure and coordination — and recording the result.
- Pedia · SoftwareBCF (BIM Collaboration Format)An open format from buildingSMART for exchanging model-based issues — with viewpoints, comments and element references — between BIM tools.
Learn
Short lessons with a quick check
- Lesson · 4 min · quizModelling to the information needDesigners lose weeks modelling detail nobody asked for, and miss the few properties everyone needs. Start from who uses each element, for what, and when.
- Lesson · 3 min · quizIFC exports other people can useAn IFC export is only as good as its settings. Map your categories to the right IFC classes, put properties where others expect them, and test the file before you send it.
- Lesson · 3 min · quizChecking your own model before you share itEvery problem you find before sharing costs you minutes; every one someone else finds costs the project days. Run the same checks the coordinator will run, first.
- Lesson · 2 min · quizDrawings that match the modelDrawings and model are two views of the same design, and both are issued. Keep them in step: one source, the same revision, and nothing drawn that the model contradicts.
- Lesson · 3 min · quizDesign reviews in the modelA design review in the model is only useful if every comment ends up somewhere it can be found, owned and closed. Review against a purpose, capture comments as issues with a viewpoint, and close them in the next model.
Do
Tools that export Excel, PDF and Word
- Tool · Excel · PDF · WordIDS CheckerUse it when a model arrives and you need to know if it meets the agreed information requirements.
- Tool · Excel · PDF · WordIFC InspectorUse it when you receive an IFC file, before you federate or share it.
- Tool · Excel · PDF · WordLOD / LOIN MatrixUse it to agree how developed each element must be at each stage.
- Tool · Excel · PDF · WordDrawing Register and TransmittalsUse it whenever drawings are issued, so everyone knows which revision went to whom.
- Tool · Excel · PDF · WordBCF Viewer & ExporterUse it to read issues from BIM tools, or send your issues back to them.
The process, at a glance
- 1HeaderSchema, application, view
- 2Spatial structureStoreys and containment
- 3ClassesProxies, names, duplicates
- 1Prepare in work in progressMandatory
The task team finishes the model it is responsible for.
Output: A model file named to the project convention
Gate: Self-check done: name, coordinates, purged views and links - 2Check the information
Run the agreed checks: requirements (IDS), naming, clashes inside the discipline.
Output: A short check report
Gate: Every failure is fixed or listed as an agreed exception - 3Share for coordinationMandatory
Move the file to the shared area with a status code that says what it may be used for.
Output: The model in the shared area, with a status code
Gate: The status code matches the purpose (e.g. coordination only) - 4Review and authorise
The lead appointed party reviews the federated set against the plan.
Output: Review comments, or an approval
Gate: Approved by the person named in the BEP - 5Publish and record
Approved information moves to published, and the previous issue to the archive.
Output: A published revision and an updated register
Gate: Register and transmittal updated
A gate is the question a reviewer asks before the next step may start. If the answer is no, the model goes back one step.
Common mistakes
What goes wrong most often on real projects.
- Modelling detail nobody asked for, and missing the few properties everyone filters by.
- Exporting IFC with default settings, so elements come out as proxies or without their properties.
- Sharing a model without running the project's own checks first.
- Moving things on drawings with 2D lines, so drawings and model disagree.
- Design review comments that never become owned issues.
Is it in place on your project?
Tick what is done — it counts towards the checkpoint on your learning path.