Creating a Manual Dormer

Reference Number: KB-00449
Last Modified: December 15, 2015

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors


How do I create a dormer using manual roof editing tools?


Dormers can be drawn manually in Chief Architect using the standard drawing tools and a few basic techniques.

To draw the dormer walls

  1. Open the Chief Architect plan in which you want to build a manual dormer or create a new plan by selecting File> New Plan  from the menu.   

    • The example below uses a 30' by 40' Cape Cod style house, with a roof pitch of 12:12.    

    • For information about creating a Cape Cod, see the Related Articles section at bottom of this page.


  2. In floor plan view, select Tools> Reference Floors> Up One Floor  from the menu to go to the second floor.  

  3. Select Build> Walls> Interior Wall  to draw an interior wall in from the exterior wall.  

    In this example the knee wall is drawn 5 feet in from the exterior wall.

  4. Use the Build> Walls> Exterior Wall  tool to draw a room that will become the dormer. Remember to draw in a clockwise direction.  

  5. Select Build> Walls> Break Wall  to separate the interior wall section in back of the dormer. Delete the section of interior wall behind the dormer.   

    The image below is the second story with dormer walls drawn.


To build the dormer's roof 

  1. Select Build> Roof> Skylight  from the menu, then click and drag to draw a rectangle within the roof plane that the dormer is being built in.  

    This rectangle will form a roof hole for the dormer to generate through.  Don't worry about the exact position or size of the rectangle right as it is drawn - it can be easily edited later.

  2. Click on the rectangle to select it, then click the Open Object  edit button.

  3. On the General panel of the Roof Hole/Skylight Specification dialog

    • Remove the check mark from the box next to Skylight.  

    • Click the radio button beside Plumb Sides.  

    • Click OK to close the dialog and apply your changes.

  4. In floor plan view, select the roof hole and use the edit handles to move its edges so that they are just outside the dormer walls.  

    • When Object Snaps  are enabled, the sides will snap to the exterior of the dormer wall.  

    • It's easiest to position the top edge of the roof hole after the roof over the dormer is in place.  

  5. Select 3D> Create Perspective View> Perspective Full Overview  to verify that the dormer walls and roof hole meet properly.   


    The edge of the roof hole should snap to the dormer wall's exterior layer.  

  6. Select File> Close View to return to floor plan view, then select Build> Roof> Roof Plane  from the menu and draw a small roof plane over each of the dormer side walls. 

    • If the Set Baseline Height dialog appears, select Over Wall Top and click OK.

  7. Join the two dormer roof planes at the ridge:  

    • Click on the ridge edge of either dormer roof plane to select that edge.  

    • Click the Join Roof Planes  edit button.  

    • Click on the ridge edge of the other dormer roof plane.   

  8. Click the Select Objects  tool, then click on the upper edge of the roof hole to select that edge.  

    • Click the Break Line  edit button, then click along the upper edge of the roof hole to place a new pivot point at that location.   

    • Do not worry about the exact location of this break as you create it.  

  9. Click on the new edit handle that is created and drag it away from the dormer and towards the ridge of the larger roof plane.  

    • As you drag, make sure that the edge of the roof hole does not touch the edge of the main roof plane it is drawn within.  

  10. Select the back edge of either dormer roof plane. Click the Join Roof Planes  tool, then click the corresponding angled edge of the roof hole. The roof plane snaps to the edge of the hole.  

  11. Repeat step 9 for the other dormer roof plane.   

  12. Select 3D> Create Perspective View> Full Overview  to see the results, and you are now ready to add a window and other finishing touches.