Modeling Building Elements

BIM for Architecture, Engineering, and Construction Curriculum


In this lesson, students explore basics techniques for using the Autodesk® Revit® Architecture software to create a building information model of a simple structure—a one-story residence. They will learn how to:

  • Model exterior and interior walls.
  • Add doors and windows to the walls.
  • Create simple floor and roof elements.
  • View the completed building model.

Modeling Exterior and Interior Walls

Many designers begin the building modeling process by creating elements that represent the exterior and interior walls of the proposed building.

In Autodesk® Revit® software, you create walls by using the Wall tool to sketch lines that indicate where walls should be placed. As you sketch these lines, 3D wall elements are created in the model and appear in other model views.

The characteristics of the walls created are determined by the properties of the wall type that you have selected. You can specify the materials and structure of the walls being placed, as well as wall height and many other physical properties.

As you place or reposition walls in the building model, Revit software automatically joins the walls that intersect.

Adding Doors and Windows

After placing exterior and interior walls, a common next step for many designers is to add doors and windows to the model.

Doors are typically placed on the exterior walls to facilitate access and egress from the building as well as on the interior walls to enable circulation between the rooms. In Revit software, doors are hosted by wall elements. You create a door by using the Door tool to choose a door component and then place it in a wall that has already been modeled.

Windows are typically placed on exterior walls of a building to provide ventilation, daylighting, and emergency egress. In Revit software, windows are also hosted by wall elements. So the pattern for procedure for placing window components is similar to doors. You use the Window tool to choose a window component and then place it in a wall element.

The characteristics of the doors and windows placed are determined by the properties of the door and windows types that you have selected. You can specify the features, sizes, and materials by selecting different types as you place them. You can also easily change the properties of a door or window by selecting it and choosing a new type.

Creating Floors and Roofs

Most buildings also include a floor underfoot and a roof overhead. So to complete the complete the building model, designers will add these elements.

The shape of many roofs is determined by the location of the walls that support it. For these roofs, a simple strategy for designing the roof is to trace the boundary of the exterior walls (which is also called the footprint), and then specify which edges of the roof will be sloped. The shape of the roof is then determined by the intersections between the sloping roof planes.

In Revit software, the Roof by Footprint tool enables you to use that simple strategy, sketching lines or picking walls that indicate the boundaries of the roof and specifying which edges should create sloped roof planes. The characteristics of the roof created—including the materials and structure, as well as the slope—are determined by the properties of the roof type that you have selected.

The steps for creating floor elements in Revit is very similar to creating roofs. You open the Floor tool and then sketch lines or pick walls to indicate the boundaries of the floor. The primary difference is that most floors are not sloped (although they can be if that is appropriate for the model). The materials and structure of a floor are determined by choosing the floor type.