Cooperation is better if the information on which we build is exchangeable, structured, unambiguous, correct, complete and reusable. The BIM base information delivery specification (BIM base IDS) is a good first step.
The second version of this application guideline builds on the previously laid foundation and is supplemented with feedback and insights from the work field. This updated BIM base IDS provides guidance and tips for the structured and unambiguous exchange of information in the construction industry.
3. What we agree on to enable collaboration
In this chapter, we discuss how the structure of aspect models is set up, so that different aspect models become interchangeable and interpretable.
3.1 File name
Always ensure uniform and consistent naming of aspect models within a project.
Coordinate the local position of (all) the aspect models. Close to the point of origin.
3.3 CONSTRUCTION LEVEL ARRANGEMENT AND NAMING
- Each aspect model uses a consistent naming convention.
- Assign all objects to the correct building storey.
- Only name construction
levels as IfcBuildingStorey.
3.4 Correct use of entities
Use the most appropriate Entity for the object and supplement it with a TypeEnumeration where possible.
3.5 Structure and naming
Consistently assign Name and Type properties to objects. The resulting combination makes it clear what it represents.
3.6 Classification system
Always assign objects a four-digit Classification code according to the latest published version used in the relevant country.
3.7 Use property sets
When exchanging properties, use the PropertySets prescribed by buildingSMART in the international standard whenever possible.
3.8 Duplicates and intersections
- Duplication within one aspect model is never allowed.
- In principle, intersections of objects within one aspect model are not allowed.
4.0 WHICH INFORMATION IS REQUIRED (AS A MINIMUM) IN ONE OF THE ASPECT MODELS
Agree on what information is to be provided by whom and when. Start with the topics in this chapter and add to them if necessary.
- Spaces are: volumes and areas, enclosed by real or theoretical boundaries, with a function in a construction.
- Create IfcSpace from spaces and name the function.
- To group spaces into
zones, use IfcZone.
4.2 BUILDING SERVICES RELATED SYSTEMS
Group installation objects belonging to the same system in an IfcSystem, when applicable.
For objects, when applicable, indicate whether the property LoadBearing is TRUE or FALSE.
For objects, when applicable, indicate whether the property IsExternal is TRUE or FALSE.
4.5 FIRE SAFETY
- For objects, when applicable, use FireRating (Resistance to fire penetration and spread) values and use FireRatingR (Resistance time to failure).
- Use the FireRating property for the Resistance to fire penetration and spread value
4.6 BUILDING PHYSICS PROPERTIES
Incorporate the relevant building physics properties into the objects.
- Assign a material (IfcMaterial) to all objects.
- In compositions, choose the dominant material.
- Be cautious with additional properties in the naming of the material.
4.8 PROJECT SPECIFIC
Determine project-specific information required for the intended BIM applications and project objectives.
Spaces are volumes and areas that are used as tools in different processes during the life cycle of a construction. Spaces are very important for reusing information. Their application are extremely diverse. Part 4.1 of BIM-based IDS explains.
Part 4.2 of BIM base IDS zooms in to building services related systems. Questions as 'What are systems' have to be cleared in a BIM.