Compared to 2D design, modeling digital building models initially involves additional effort. It is therefore particularly important to carefully tailor the modeling effort to the respective design phase—the more objects included in an early model, the greater the expected effort required for changes. All articles in the modeling guides are structured according to the principle of effort-optimized, phase-appropriate detailing. However, a few general statements can be made at a higher level, which will be described in this article.
In this context, it is extremely helpful to keep in mind the graphical, scale, and content requirements of the building symbol regulations: In Germany, Austria, and Switzerland, for example, floor plans and sections do not provide information about the building materials used in walls and ceilings until the submission phase at the earliest. The article on the phase model describes the theoretical background and is recommended for further reading.
Keywords: phase, modeling, building, model, planning, phase model, detailing, detail, phase-appropriate
Despite all the special cases and exceptions, it is possible to formulate a number of software-platform-independent guidelines for phase-appropriate modeling of digital building models:
As much as necessary, as little as possible
Many users develop a remarkable tendency to over-detail their models—which is often neither effective nor cost-efficient. Ask yourself the following questions:
- Which elements must actually be included in a model during a specific planning phase? For example, does it make sense to model handrails in a very early planning phase if the staircase in question is still subject to significant changes?
- How detailed do elements actually need to be? Consider whether you would even be able to recognize the modeled elements in a scale drawing appropriate to the phase—for example, plaster layers in a 1:100 scale design. For more on this, read the article “Detailing with Purpose.”
- What level of detail do I need in the evaluation phase of planning, e.g., for quantity and mass calculations? What exactly do I want to evaluate at this stage?
Change-optimized modeling
Changes to a design are part of everyday work. To minimize the effort required to make changes in digital building models, please note the following:
- Especially during the early planning phases, use the multi-layer method as much as possible when working on walls, ceilings, and roofs—this allows you to quickly and easily make changes to different layer configurations from a central location.
- Pay attention to the reference lines or reference planes of the objects—in which direction “can” a wall or ceiling become thicker (e.g., a wall along an emergency exit)
- Use floor or reference level links - Link the vertical boundaries of walls and columns to reference points (e.g., the top edges of structural walls to the bottom edge of the structural floor slab above) to enable automatic adjustment when floor heights change
- Identify repetitive elements or component groups (e.g., standard floors, apartment and office types, furnishings, etc.) and then work with modules that you can modify centrally.