By Martin Phelps
Following the previous blogs relating to “Dormers”, there is another type of “Dormer” that can be constructed in Revit, this is creating a “Dormer” by modifying the main roof “Footprint”. Create the main roof and attach all the walls using “Attach Top / Base”, as per Figure 1.
For ease, activate the “Floor Plan” on which the roof was created, in this case it’s “Level 1”. Select the “Roof” and select “Edit the Footprint”.
Note:- Prior to editing the “Roof Footprint” it may be advantagous to create “Reference Planes” which can act as “Split” line guides when creating the “Dormer” roof edges, as shown in Figure 2.
Select the “Split Element” command, located in the “Modify |Roof” tab of the ribbon menu, as shown Figure 3.
Split the line of the location of the “Dormer” into four, in this example it’s the lower horizontal line, these will automatically have a slope attached, as per Figure 4.
Note: - Zooming in on the lines can make this task easier.
Select each of the newly created lines and remove the allocated slope, as per Figure 5.
Using the “Slope Arrow” command located in the “Modify | Roofs > Edit Footprint” tab, as shown in Figure 6.
Add a “Slope Arrow” to each of the newly created lines, so that both arrow heads point to the centre line of the “Dormer”, as shown in Figure 7.
Note: - Check that the lines making up the roof profile have no gaps between them or overlap over lines within the profile. If these states exist the roof will fail and an error will be displayed.
Select the “Green Tick” to confirm the edit to the “Roof Footprint”. Activate the “3D View”, and if not set change the “Visualisation Style” to “Shade”, as shown in Figure 8.