Revit - Dormer Variation 2

by Martin Phelps

Extruded curved roof with extruded curved dormers

Figure 1.

The walls comprising the building are the same as in my previous blog “Dormer Variation 1”. Use the following link https://www.cadlinecommunity.co.uk/hc/en-us/articles/360011566638 to view.

The main roof has been created using “Roof by Extrusion”, using an “Arc” as the “Profile”, overlapping each end of the building by 500mm.

To simplify the process, the “Dormer” walls and roof are still created away from the main model, with the dormer roof being created using “Roof by Extrusion”, again using an “Arc” as the profile, as shown in Figure 2.

Figure 2.

Once created, the “Dormer” roof and walls can be copied and located in the main building, as shown in Figure 3.

Figure 3.

To aid clarity, view the model in 3D and set the visualisation style to “Wire Frame”, using the “Join / Unjoin Roof” tool. Select the edge of the of “Dormer” roof, then select the main roof. The “Dormer roof will either extend or trim to meet the main roof, as shown in Figure 4.

Figure 4.

Select the “Dormer Opening” tool from the “Architecture” tab in the ribbon. Select the main building roof in which the “Dormer” cut will appear, select the “Dormer” roof and then select the two side walls and the front wall of the dormer, as shown in Figure 5.

Figure 5.

The cut lines are automatically created from the selected components and appear in magenta. However for the Dormer opening to be created, the lines must join to create a closed shape.

Due to the curves of both the main roof and the dormer roof, the “Extend / Trim To Corner” tool may not work, so to ”Join” the lines, select each line in turn and use the blue circular grips to create the closed shape, as shown in Figure 6.

Figure 6.

Confirm the edit and complete the command by selecting the green tick in the ribbon menu.

The “Dormer” walls now have to be joined to the main roof and the dormer roof. In most cases selecting the wall and using the “Attach Top / Base” command will create the desired effect, however with a curved roof there may be a problem.

Reduce the length of the side wall so that the wall is within the length of the dormer cut as shown in  Figure 7.

Figure 7.

Once the side walls has been attached to the both the main and the “Dormer” roof, the wall can be extended as shown in Figure 8.

Figure 8.

If an “Error Alert” dialogue is displayed as shown in Figure 9. the wall is too long. Cancel the command and set the length of the wall to a smaller value.

Figure 9.

Repeat this process for the other side wall also using the “Attach Top / Bottom” command.

A window may be added to the front “Dormer” wall if required.

To finish, copy the “Dormer” roof, side walls, front wall, window and dormer opening to additional locations along the main roof as shown in Figure 10.

Figure 10.

Note :- Using reference planes can make it easier to locate the component position.