So now that we’ve added some circulation to the interior of our little home, what we’re going to look at next is adding a roof. In Revit there are a couple different ways to create a roof, but today we are going to use a Roof by Footprint followed by a Roof by Extrusion.
You can download the BIM model so far by clicking here, please keep in mind that this BIM model will only open in Revit 2012 or a later release. If you’ve been following along from the beginning, open your model and access the Level 2 plan view.
From the Build Panel, in the Home Tab, access the Roof tools. For this first step we’ll use Roof by Footprint. In the offset field under the ribbon, enter 2’-0”, and select from the Draw options, the Pick Walls tool. Select each exterior wall, other than those dealing with the vestibule, and make sure to leave Defines Slope checked on each wall you choose.
Now with each line properly trimmed at the corners, select all four lines and in the Properties box, change the Slope from 9”/12” to 4”/12”.
Accept your roof sketch by clicking on the Green Check mark. Using the Default 3D view, inspect the new roof you have added to your building. If you access an Isometric view, using the View Cube, you should now have something that looks like this.
For the next step, we’ll create a barrel vault roof for our vestibule to give this little home some character. Access the South Elevation and from the Roof tools, select Roof by Extrusion.
Revit will now ask you to pick a plane to start the extrusion from. If the Pick a Plane option isn’t already selected, select it, if it is select, click OK. Next, use the crosshairs to select the front face of the vestibule. You will know it is ready by the blue outline of the face of the wall. In the dialog box that appears, select Level 2, and leave the offset as 0’-0”.
- To create the extrusion profile we will select the Ellipse tool from the Draw options and start the centre at the top of the vestibule wall, give the first radius a value of 2’-10 ¾”, the second width radius should be 7’-4 1/8”. Don’t worry if your ellipse isn’t exactly centred or exactly to these dimensions, we can nudge it around and edit the dimension after.
- With the Ellipse in place, draw a Line along the horizontal axis from one side to the other.
- Using the split tool, create two splits on the bottom side of the Ellipse
- Use the Trim/Extend tool to fillet the top half of the Ellipse to the centre line
- Remove the lower portion of the ellipse and delete the centre line
- Click the Pick Lines tool from the Draw Options, enter 6” and offset our top Ellipse line outward.
- Remove the original top ellipse curve and click the Green Check mark to accept the sketch
Inspect the new extruded roof in an Isometric view, use your Default 3D View and the View Cube to take a look. If you’re having problems seeing where the two roves connect, switch your Visual Style to Shade mode and it will become much clearer. Now our next step is to combine these two into one roof. Using the view cube, switch to an isometric view that shows the back extruded face of our new barrel vault roof.
Access the Modify Tab, and in the Geometry panel, locate the Join/
Unjoin Roof tool.
- Select the extruded end of our roof on the other side of the house
- Click on the front hip of our first roof
The result should be a perfectly joined roof. In the Default 3D View, select the roof and notice there are grips that you can use to modify the extrusions. We’ll use this to increase the overhang of the barrel vault roof in the front. We can edit the slope of our main roof in the same manner. Also, at any time, you can edit the sketch of the main roof, but selecting the roof, clicking the Edit Footprint button, and adjust accordingly. Try unchecking the Define Slops on the edge for the North Elevation and seeing what results you get when you accept the sketch.
To finish up, we’ll add some gutters to the roof, and connect the front vestibule wall using the Attach Top/Base feature.
- In an isometric view looking from the south, select the front face of the vestibule.
- Click on the Attach Top/Base tool
- Select the barrel vault roof
Notice the void is filled with the front wall of the vestibule
Next in the 3D Default View, select the Gutter tool from the Roof Tools and simply click on each edge of the main roof to apply the gutters. For the south elevation, you will need to create one gutter, adjust it’s length, and then repeat the process for the other side so it doesn’t go through the barrel vault.
From the Roof tools, select Fascia and repeat the steps to create fascias. Note, the fascia tool can only be used on linear profiles such as gable ends, the barrel vault will need a fascia applied using a massing technique.
So this conclude our exercise in the basics of creating rooves. Once again, I hope your having fun with the experience of BIM. Your feedback is welcome at info@idesignsol.com. Thanks for reading!
Travis Van Clieaf
