Creating an opening in a Revit slab involves using specialized tools designed for different scenarios, from simple cutouts in a single floor to complex vertical shafts penetrating multiple levels. The primary methods include using Shaft Openings, Opening by Face, and Editing the Slab Boundary.
Understanding Slab Openings in Revit
Revit offers flexible tools to create penetrations in floor elements. Choosing the right method depends on whether the opening needs to extend through multiple floors (like for an elevator or stairwell), if it's a simple cutout in a single slab, or if it's an integral part of the slab's overall shape.
Method 1: Shaft Openings (for Vertical Penetrations)
Shaft Openings are ideal for creating vertical penetrations that cut through multiple floors, roofs, and even ceilings simultaneously. This tool maintains the opening's alignment across different levels, making it perfect for elevator shafts, stairwells, or utility chases.
How to Create a Shaft Opening:
- Access the Tool: Navigate to the Architecture tab on the Revit ribbon. In the Opening panel, click on Shaft.
- Define the Sketch Boundary:
- Revit will enter sketch mode, allowing you to draw the perimeter of your opening. You have flexible options for defining this boundary:
- Draw Lines and Shapes: Use drawing tools like Line, Rectangle, Circle, Arc, or Polygon to sketch the desired shape of your opening directly on a floor plan view.
- Pick Walls or Lines: A highly efficient option is to use the "Pick Walls" or "Pick Lines" tool. This allows you to select existing walls or model lines in your project, and Revit will automatically use their geometry to define the opening's sketch boundary. This is particularly useful when creating shafts defined by existing structural elements.
- Revit will enter sketch mode, allowing you to draw the perimeter of your opening. You have flexible options for defining this boundary:
- Set Constraints:
- In the Properties palette, under the Constraints section, define the vertical extent of your shaft:
- Base Constraint: Select the lowest level your shaft should start from.
- Base Offset: Enter a value to offset the bottom of the shaft from the base constraint level (e.g., a negative value to extend below the floor).
- Top Constraint: Select the highest level your shaft should extend to.
- Top Offset: Enter a value to offset the top of the shaft from the top constraint level.
- In the Properties palette, under the Constraints section, define the vertical extent of your shaft:
- Finalize the Opening: Once the sketch is complete and constraints are set, click the Finish Edit Mode (green checkmark) button in the ribbon.
Benefits of Using Shaft Openings:
- Multi-Level Cutting: Automatically cuts through all intersecting elements (floors, roofs, ceilings) within its defined vertical extent.
- Centralized Control: The entire vertical opening is controlled by a single object, simplifying modifications.
- Easy Adjustment: You can adjust its size, shape, or vertical range from any view.
Method 2: Opening by Face (for Single Slab Cutouts)
The Opening by Face tool is used to create an opening in a single element's face, such as a specific floor slab, wall, or roof. This is suitable for localized cutouts that do not need to penetrate multiple levels.
How to Create an Opening by Face:
- Access the Tool: Go to the Architecture tab, and in the Opening panel, click on Opening by Face.
- Select the Element: Click directly on the face of the slab where you want to create the opening. Revit will automatically enter sketch mode.
- Sketch the Opening: Use the available drawing tools (Line, Rectangle, Circle, etc.) to define the shape and size of your opening on the selected slab face.
- Finalize the Opening: Click the Finish Edit Mode (green checkmark) button.
Benefits of Using Opening by Face:
- Precision: Allows for very precise placement and shaping of an opening on a single element.
- Specific Application: Ideal for isolated cutouts, such as a drain opening in a bathroom floor or a small access hatch.
Method 3: Editing the Slab Boundary (for Integrated Openings)
For simpler, single-slab openings that are fundamentally part of the slab's overall shape, you can directly edit the slab's boundary sketch. This method integrates the opening as an internal void within the slab definition.
How to Edit the Slab Boundary:
- Select the Slab: In a floor plan or 3D view, select the floor slab you wish to modify.
- Edit Boundary: In the Modify | Floors contextual tab, click Edit Boundary (or Edit Sketch).
- Draw the Inner Loop: Revit will enter sketch mode, showing the existing boundary of your slab. Draw a closed loop inside the main boundary lines. This inner loop will define your opening.
- Rule: For an opening to be created, the sketch must contain at least two closed loops: an outer loop defining the slab's perimeter and one or more inner loops defining the openings.
- Finalize the Slab: Click the Finish Edit Mode (green checkmark) button.
Benefits of Editing the Slab Boundary:
- Direct Integration: The opening is an inherent part of the slab's geometry.
- Simplicity: Quick and straightforward for simple, single-slab cutouts that don't need independent control.
Choosing the Right Method
The best method depends on your specific project needs:
| Feature | Shaft Opening | Opening by Face | Edit Slab Boundary |
|---|---|---|---|
| Purpose | Vertical penetrations (multi-level) | Single-element cutout | Integral part of slab shape/cutout |
| Cuts Through | Multiple floors, roofs, ceilings | Only the selected element | Only the selected selected slab |
| Ease of Adjustment | Centralized control, easy to modify stack | Individual control for each opening | Directly tied to slab's properties |
| Definition Method | Sketch (draw lines or pick elements) | Sketch | Sketch (inner closed loop) |
| Typical Use | Stairwells, elevators, large chases | Floor drains, small access panels | Atriums, custom-shaped floors with voids |
