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Message: Placing an automatic dormer.

Reference Number: KB-00751 Last Updated: 11-10-2014 02:52 PM

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors or Chief Architect Lite
Home Designer Professional

QUESTION


When I try to create an automatic dormer, I sometimes get a warning message.  What does the message mean and how can I avoid it?



EXPLANATION


The Automatic Dormer tools allow you to create either a structural or floating dormer complete with walls, roof planes, a roof hole and even a window with a single click.  Both tools do require certain conditions before they can be created, however:

 

  • Both types of Automatic Dormers must be located completely within a single roof plane. 

  • Auto Floating Dormers cannot intersect interior walls in the living space or attic space directly below.

  •  Auto Dormers must intersect knee walls running perpendicular to the slope of the main roof plane in the living or attic space directly below.

  • Auto Dormers must locate a roof plane at the lower front dormer wall and a ceiling at the upper back.  Put another way, the part of the roof plane where the front of the dormer is found must be lower than the ceiling height of the living space behind the dormer. 

  • Both types of Automatic Dormers will always face the eave of the roof plane in which they are placed.  The front dormer walls will always be parallel to the main roof plane's baseline.

  • Both types of Automatic Dormers must be placed far enough apart from other dormers that they do not share the same space.





ANSWER


This article discusses the causes and resolutions for the common warning messages that display when we try to place an Automatic Dormer in an incorrect location.
 

Requirement: An Automatic Dormer must be located completely within a single roof plane.

By definition, a hole in an object must be completely enclosed by that object - the hole cannot touch or extend past one of the object's edges.  And, one of the objects included in every Automatic Dormer is a roof hole; as a result, Automatic Dormers must be completely enclosed by a single roof plane and cannot be positioned along a roof plane edge. 
In fact, since roof planes have both a thickness and a pitch, Automatic Dormers have to be set back from the eave or ridge edges. The exact setback distance required will depend on the roof plane's depth and its pitch.
There are a number of Information or Warning messages that may display if you attempt to place or move an Automatic Dormer into a position that violates this requirement:
 
  • You must click over a roof plane, and that plane should have a pitch greater than 1 in 12 (about 4.76 degrees - 6 in 12 or greater is recommended) in order to build a dormer. 

  • This dormer does not fit on the roof plane at the point where you clicked.  Try placing the dormer closer to the roof eave, changing the dormer height, or increasing the pitch of the roof plane. 

  • Not enough room for hole in roof beneath dormer, so it will not be made properly until you resize or move this dormer.

  • Cannot fit ­eyebrow dormer in this space.

  • Shed dormer roof pitch is too high.

  • Dormer roof does not meet base roof, probably near the top. You may need to move the dormer down the roof or lower its height.

To avoid warnings such as these:
  1. Be sure that you click completely inside a roof plane when creating an Automatic Dormer.


  2. Click further away from the ridge (closer to the eave) to place the dormer. 

     

    • If you are trying to place a dormer near the eave or a side edge of a roof plane, place it well inside the roof plane, then move it towards the edge after it is created.
       
  3. Specify a lower height for new dormers in the Dormer Defaults or the dormer's Dormer Specification dialog. 

       

  4. Specify a shallower pitch for new dormers in the Dormer Defaults or the dormer's Dormer Specification dialog. 

     
     

  5. Specify a steeper pitch for the main roof plane. 

     
     


Requirement: Auto Floating Dormers cannot intersect interior walls in the living space or attic space directly below.

Auto Floating Dormers  are non-structural dormers that bear on the roof and do not have supporting walls beneath them.  Because this is their intended purpose, they cannot have interior walls directly below them.
There are several messages which may display if you try to place or move an Auto Floating Dormer into a position that violates this requirement:

  • Cannot create dormer here because existing walls are in the way.

  • Cannot build walls for this dormer here because existing walls are in the way.
    It needs to be moved to another position.

  • Walls for a floating dormer are in the same area and on the same floor as the
    stairwell will be (the floor above the stairs). This floating dormer should be
    moved to the next higher floor, so its walls will not interfere with the stairwell.

In some situations, you can move the interior wall that is preventing the dormer from generating, or you can place the dormer in a location where interior walls are not present. Perhaps the best way is to place the Auto Floating Dormer in the attic space above the living area.

To move an Auto Floating Dormer up one floor
  1. Click on the Auto Floating Dormer to select it.


  2. Select Edit> Cut  from the menu to remove it from your drawing and copy it to the Windows Clipboard.


  3. Select Tools> Reference Floors> Up One Floor from the menu to go up one floor.


  4. Select Edit> Paste> Paste Hold Position  from the menu.


  5. If you'd like, you can turn on the Reference Display  to confirm its correct location relative to walls and other objects on the floor below.   

 

 

Requirement: Auto Dormers must intersect knee walls running perpendicular to the pitch of the base roof plane in the living or attic space directly below.

In order to place an Auto Dormer , which is a structural dormer with walls that extend down to the floor of the living area below, it is necessary to place a knee wall that runs perpendicular to the base roof pitch, or parallel to that roof plane's baseline. The space behind the knee wall must also be specified as an Attic room.

If you try to place an Auto Dormer at a location that does not meet these requirements, these messages may display: 

  • Cannot find walls for the room to which the back of this dormer should connect. 

  • Normally expect room type to be ATTIC on the exterior side of this dormer wall.

 

To learn how to place an Auto Dormer , see article 648, How to create an automatic dormer.

 

 

Requirement: Auto Dormers must locate a roof plane at the lower front dormer wall and a ceiling at the upper back.  

In order for an Auto Dormer  to be placed, the program requires that the roof plane at the point where the dormer's front wall is placed be lower than the ceiling of the living space behind the dormer.    

If you try to create an Auto Dormer at a location where the ceiling of the living space is too low relative to the roof plane on which the dormer is being placed, one of these messages will display:

  • Ceiling too low on this floor to create auto dormer.  Try creating dormer on the floor above.

  • New dormer is positioned too high up on the roof to match its ceiling level with
    the room behind it. The dormer front wall would be less than six inches high.

  • The height of an Auto Dormer should match or be lower than the flat ceiling
    height of the room behind it, even if "Ceiling Over this Room" is unchecked.
    For best results, check "Set to Existing Ceiling" in the Dormer Specification
    dialog or raise the ceiling height of the room behind the dormer.

  • Room or enclosed area in front of or beside dormer should be an Attic or other
    room with "Ceiling Over This Room" unchecked, or if not, its ceiling height
    should be set as high or higher than the dormer's.

  • Ceiling height of attic room or enclosed area in front of or beside dormer
    should be set as high or higher than dormer ceiling height.


 

Another way of looking at this situation is that the roof is too high relative to the ceiling in the living space. This warning is often encountered when we try to place an Auto Dormer in a roof plane with a baseline higher than the ceiling height of the living area below.

To resolve the situation, you can place the dormer in the attic space above; however, to create a structural dormer located in the living space, it is best to rebuild the roof planes at a lower height and then place the dormer. 



Requirement:  Automatic Dormers always face the eave of their base roof plane and the front dormer walls are always parallel to its baseline. 

Neither of the side walls of a dormer can be aligned with a wall below them, even if the dormer is placed in an attic space. The only wall in an Automatic Dormer that can be positioned over a wall in the living space below is the front wall - but only if the wall below is perpendicular to the base roof plane's pitch. If you try to position an Automatic Dormer so that its front wall is located over a wall that is not perpendicular to the base roof plane's pitch, this message will display:

  • To extend this wall up to make a dormer front, the wall must be parallel to the baseline of the roof plane under the dormer. 

There are a number of ways to avoid the warning:

  • Do not place either type of automatic dormer above either an interior or exterior wall that does not run parallel to the pitch of the main roof plane.

  • To place a dormer over an interior wall that is parallel to the main roof pitch (or perpendicular to the baseline of that roof plane), turn on the Reference Display  and place the dormer in the attic space above the living area.  Notice, though, that the front dormer wall will always face the eave edge of the roof plane that it is placed on - it is not possible make it face another direction. 

  • It is not possible to place a dormer over an exterior wall running parallel to the main roof pitch, even in attic space. 

     

    Requirement:  Both types of Automatic Dormers must be placed far enough apart from other dormers that they do not share the same space.

     

    While it is possible for some objects in the program, such as plants and CAD items, to share the same space, the components that make up automatic dormers, including walls and roof holes are not capable of doing so.  

    If you try to create a new automatic dormer or move an existing dormer too close to another one, this message will display: 

    • New dormer is positioned too close to another dormer. 

    To avoid this warning message, click further away from any existing dormers when creating a new one.  Remember that the point where you click will be the center point of the front wall of the new dormer.  If, for example, your default dormer width is 72" (six feet), you will need to click at least 36" (three feet) away from an existing dormer in order to have enough room for the new one.