Creating detailed construction documents marks the beginning of the conversion of a proposed design into a constructible project. No drawing set is complete without descriptions of the materials and the assembly details, which is why adding annotations, linework, and detail components is a crucial phase of the complete BIM workflow.
The process of detailing is often used to present:
- Project information not captured in the building model.
- Information that goes beyond the level of detail represented in the building model.
- Revisions or corrections needed to clean up the display of model elements.
The following annotation categories are often added to model views to transform them into fully functional construction: dimensions, detailing (detail lines, regions, components, revision cloud, and detail group), text, element and view tags, and symbols. Annotations and drafting detail are view-specific and do affect the underlying building model.
In this lesson, students explore the progressive layering of detail describing the construction of a single wall and its features by creating a building section, drilling down to a wall section, and creating details to illustrate the key connections between the wall and other building elements.
Creating Annotated Section Views
Many designers begin the building modeling process by creating elements that represent the exterior and interior walls of the proposed building.
The detailing process often begins by creating section views of the entire building and specific wall assemblies.
Building sections often serve as road maps that point the way to related wall sections and connection details. Wall sections typically display the detailed layers in a wall assembly and how they connect to other building elements.
Since these section views are automatically updated when changes are made to model elements, internal consistency of the model views is ensured. The BIM methodology can save a great deal of time otherwise spent cross-referencing changes and looking for consistency errors that are typical in paper-based workflows.
Creating Details and Callouts
Detail views are typically added to a set of construction documents to present information at a larger scale or a finer level of detail needed to accurately understand specific elements and connections between elements. Although detailing can be a tedious process, it is an essential step in converting designs into realizable construction documents.
Details bridge the gap between design and construction, conveying crucial information to the builders and contractors about how a design should be built. While it would be unrealistic to try to model every single construction detail in 3D, details enable design professionals to quickly convey practical assembly information in an easily shared 2D form.
Using Autodesk® Revit® software, details can be created in two ways:
- Detailed Model Views display the actual building model geometry at a larger scale. Detailed model views are created by adding callouts or section cuts to other views.
- Drafting Views can be generated from scratch, independent of the building model, or by importing an image or CAD detail as a starting point.
It is common practice to incorporate details from product manufacturers or even standard details from an office library in the project drawings. Drafting views provide a convenient vehicle for including this model independent information into the project.
References to details can be placed on larger-scale views using view tags, such as callout tags or section tags. These callouts and section tags provide markers that lead to the detail views and increase the coherence and usability of the document sets by pointing users from one view to other related views. Therefore, we should plan our use of views and callout or section tags to provide a logical sequence moving from large-scale view to greater levels of detail.
View tags (such as elevation tags, section tags, and callout tags) provide pointers to related views in two ways:
- Double-clicking a view tag opens the referenced view in a manner similar to a hyperlink.
- Information about where a view has been placed on sheets is displayed in the view tag. The tag shows both the sheet number and the view number relative to that sheet.
View tags are dynamically updated to show the proper sheet number and view number as views are placed or moved between sheets. This real-time coordination prevents errors in cross-referencing, thus creating more reliable documents and saving costly rework.