How to Model Complex Roof Structures in Revit

Edited 6 months ago by ExtremeHow Editorial Team

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Creating complex roof structures in Autodesk Revit can be a challenging task, especially for users who are new to the software. However, with the right techniques and understanding of Revit's tools, you can create complex roof designs with accuracy and efficiency. The purpose of this guide is to provide a comprehensive walkthrough outlining the steps and methods required to model complex roof structures.

Understanding ceiling elements in Revit

In Revit, a roof is not just a component of a building model; it is a system that includes various elements used to assemble the top perimeter of a structure. Roofs can be created using a variety of methods, and each method offers unique advantages for certain types of roof geometry.

• Roof by footprint: This method is suitable for simple roof designs, where you mark the perimeter of the roof directly on the floor plan.
• Ceiling by Extrusion: This is best used for irregularly shaped ceilings, where a profile is sketched on a vertical work surface and then extruded horizontally.
• From roof faces: This technique uses a mass object to obtain the shape of a roof. It allows you to create complex shapes by applying roofs to the faces of mass forms.

Set up your model

Before creating a complex roof, make sure your model is set up properly. Accurate levels and grids are essential because they determine the framework within which the roof and other elements will be placed.

1. Establish levels: The levels will define the height at which the various elements of the building exist. Make sure all necessary levels are created, including any intermediate levels for different sections of your roof.
2. Set up a grid: Use a grid to organize the layout of your building. Grids are especially useful when dealing with complex roof structures where alignment and symmetry are important.

Design of roof structure

When designing complex roofs, it is important to map out your design and plan the approach. Below are some strategies to consider:

Create a collective model

For highly complex roofs, especially roofs with freeform shapes, it can be helpful to first create large models of the shape of the roof you want using the Massing tool in Revit. The large models can serve as a basis for applying more precise roof elements later. This process includes:

• Go to the "Massing & Sites" tab and select "In-Place Mass".
• Mold the mass into the desired shape of the ceiling using tools such as "Extrude", "Blend" and "Revolve".
• Applying a roof to the surface of a mass using the roof by face method.

Rooftop usage as per footprint

To build a roof by footprint:

1. Select the "Roof" dropdown in the "Architecture" tab.
2. Select "Roof by Footprint". This will open Sketch Mode.
3. Draw boundary lines directly on the floor plan view. Use lines, arcs, and splines to define complex shapes.
4. Modify the slope of the roof by selecting and editing slope arrows or defining edge properties.

Remember, the "Roof by Footprint" method is best suited for flat roof slopes. For more undulations or organic geometries, you may need to use "Roof by Extrusion" or "Roof by Face".

Roofing application by extrusion

Extruded roofs are created by defining a 2D profile that is extruded to create the roof geometry.

1. After selecting "Roof by Extrusion", specify the plane on which you want to sketch the profile.
2. Create a section profile of your roof. This can be as simple or as detailed as needed.
3. Finalize the extrusion, determining how deep the profile will protrude.

Making a roof with a rafter

The roof by face method allows you to apply roofing to a large surface area. Use this option for highly complex roofs that involve curves or unconventional shapes.

1. Conceptual Mass Create a solid or void form in an environment.
2. Finish the mass and go to the roof tool, selecting "Roof by Face".
3. Select the surface you want to convert into a ceiling.

Making the ceiling look refined and detailed

Once you have decided on the basic shape of your ceiling, it's time to refine it and add details. Revit provides many tools to help you achieve the desired aesthetic and functional requirements.

Editing ceiling properties

Use the Property palette to adjust parameters such as material, thickness, and slope. Make sure these properties conform to your project's design specifications.

Adding Ceiling Features

• Soffits, fascias and gutters: These elements can be added to provide an elaborate finish for your roof. They contribute to the roof's drainage capabilities and enhance its overall appearance.
• Roof openings: To include skylights or mechanical penetrations, use the "Openings" tool available in the Modify > Geometry panel.

Splitting and Patching Roofs

For very complex designs, you may need to split roofs and apply different pitches or materials to the sections. The Split tool allows for separation, while the Patch tool can refine intersections.

Ensuring structural integrity

While aesthetics are important, it is vital to ensure that your ceiling can withstand structural loads. In Revit, structural integrity can be checked using the following methods:

• Using analytical models to simulate load scenarios.
• Consulting with structural engineers to validate your design assumptions and calculations.

Collaborating with the design team

Complex roof structures often require collaboration between architects, structural engineers, and MEP engineers. Use Revit's collaboration tools to streamline this process:

• Worksharing in Revit allows multiple team members to work on a model simultaneously.
• Use linking and coordination tools to ensure that all disciplines are in sync and that any conflicts are resolved early in the project.

Conclusion

Modeling complex roofs in Revit involves a combination of creative exploration and technical rigor. By mastering the tools and techniques outlined above, you can efficiently create beautiful and structurally sound roof designs. Remember that practice and experience are key, and don't hesitate to explore Revit's extensive documentation and forums for continued support and learning.

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