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ArchiCAD Basic Training – Module 4
4-2. Intro to Roof Construction for ArchiCAD 15

ArchiCAD Training –  (Quick Start Course – 4-2)

This 29 minute lesson teaches the methods used for constructing roofs in ArchiCAD 15.

A box of 4 walls is created off to the side of the ground floor (20’x30′ or 7 m x 10 m), then the walls are selected and multiplied 6 times using the Multiply command (right-click, select Move > Multiply). The Multiply dialog box is briefly examined, and the Drag / Increment option is chosen. These groups are spaced 30′ or 10 m apart; each will be used to demonstrate a different method for drawing roofs.

1. Shed Roof: the roof tool is activated, and the single plane geometry method is selected, with rectangle construction mode. The first two clicks are placed at the outside edge of the left hand wall, and define the “pivot line” for the roof, a virtual line in space where the roof is horizontal  at the height set in the roof dialog box or Info box. The third click with the “eyeball” cursor is made within the building outline, and indicates the upward slope direction. Then (in the case of the Rectangle creation mode) two clicks place the opposing corners of the shed roof.

A marquee is placed with a heavy border (to be able to see all stories within that area) and then these walls and roof are viewed using the right-click > Show Selection/Marquee in 3D (or keyboard shortcut F4 on Mac, F5 on PC) command. The roof is selected and its slope is adjusted in the Info box.

The four walls are selected using the Select All shortcut (TIP: activate the Wall tool in the Toolbox, then use the Edit menu > Select All Walls command or Command-A or CTRL-A), then their height is increased in the Info box. With the walls still selected, the Design menu > Crop to Single-plane Roof… command is used. The walls are now cropped to match the current slope of the roof.

The roof slope is adjusted downwards, but the walls stick up above it; they are then cropped again with the same command. The roof is tilted higher, but the Crop to Single-plane Roof command doesn’t make the walls grow, so in the Wall Settings dialog the Undo All Crops button in the Model panel is used to restore the walls to full height so they can be cropped properly.

After undoing the last crop, a superior method of cutting the walls under the roof is demonstrated using the Design menu > Connect > Trim Elements to Roof/Shell command. In 3D, the walls are selected, then the Trim Elements to Roof/Shell command is activated. The roof is clicked on to select it as the trimming element, then the part of the wall beneath the roof is clicked to indicate that this is the part of the wall that should be retained (if you click on the part of the wall above the roof, then the lower part will be discarded). This method keeps an ongoing connection between the elements, so if the roof slope is adjusted the walls continue to be trimmed underneath them.

Finally, the roof overhang is created by selecting the roof on the floor plan and using the pet palette option to Offset all edges. (TIP: this option is available when any polygon element is selected and you press down on a corner node point; it’s located in the upper right of the pet palette). A gesture confirms the direction (to expand or contract the polygon) and the tracker is used to set an offset of 1′-0″ or 300 mm for the roof eaves.

2. In the second set of walls, the new Multi-plane geometry method is selected, and the gable rectangle construction option is chosen. Two clicks – one at the upper left and one at the bottom right – and the two roof planes forming a gable are created instantly. Eave overhangs are included automatically, based on the settings in the Multi-plane panel in the Roof Settings dialog box.

The roofs appear with a dense dotted line, making them less prominent onscreen. To modify this, select the roof element, then in the Roof Settings > Floor Plan and Section settings panel > OUTLINES items change the Overhead Lines parameter to any desired linetype — Dashed was chosen to make the roof stand out better onscreen.

The walls and this multi-plane roof element are viewed in 3D; the roofs create a gable end, but the end wall needs to be extended and trimmed. The wall is selected, then its height is changed to rise above these gable roofs, then it is trimmed using the Trim Elements to Roof/Shell method.

3. Next, a similar gable roof is created in order to study how roof planes can be set independently to different slopes. The roof element is selected, and the mouse is pressed down on the left side pivot line; from the pet palette, the new option to edit an individual roof plane is chosen. In the dialog box, the pitch angle is adjusted. After confirming the change, the roof reconfigures and the ridge line is now offset from the original mid-point.

The process is repeated while looking in 3D. When the multi-plane roof is selected, the reference lines (which include the two pivot lines) are shown in a blue color, and float at the elevation base height for the roof, while the outline for the roof is shown in green and follows the pitch of the roof planes. To edit the slope of one plane, the pivot line on that side is pressed with the mouse, and the same pet palette option for editing an individual roof plane is chosen. The process works the same as on the floor plan.

Returning to the floor plan, one additional technique is shown: one can press down on the ridge line and use the pet palette option to move or displace the ridge line. This does not seem to allow precise positioning, and seems to cause some other alterations to the eave offset distances, so the change is Undone. The pivot line is used to again set the roof slopes to be identical and symmetric.

4. The process of creating a set of gable roofs then adding in a new hip roof manually is unnecessary in ArchiCAD 15. We skip forward to the next step.

5. To create a multi-plane roof with hips is very easy in ArchiCAD 15. Use the Multi-plane geometry option, then select either the Hip Rectangle or the Complex construction option. With the Hip Rectangle method, simply click on one corner then the opposing corner, and the entire system is drawn instantly. With the Complex construction option, one can click on each of the corners to create the polygon outline.

Since the default settings of the Roof tool had not been changed, the dense dotted outline is shown. To change it to the preferred dashed lines, the eye-dropper picks up the settings from the previous roof, and the syringe is used to inject the changed settings into the new roof, which then changes to match.

6. The Multi-plane > Complex construction option is used again, but this time the magic wand is used to automatically trace the outline of the walls instead of clicking each point. (NOTE: you can bring up the magic wand by holding down the Space bar on the keyboard, or choosing the Design menu > Outline Polygon with Magic Wand command. To work, a suitable drawing tool should be active, and no elements may be selected.)

When the roof configuration needs to be adjusted, this may be done easily by editing the Multi-plane roof element. To delete one of the end hips is done in a different fashion than in previous ArchiCAD versions. Instead of selecting and deleting the plane, then adjusting the adjoining roofs, the node point at the top of the hip is moved individually using the new pet palette option for this purpose (the icon shows a single hip node point being repositioned).

Move this hip node to make the hip plane steeper or shallower. If one adjusts it to be in line with the adjoining end points, the hip plane disappears, and the two adjoining roofs are adjusted to create a gable end in its place. Note that the gable end repositions itself to be in line with the wall face, and will likely need to be adjusted in a separate editing operation.

To offset the eave of the gable, press down on the reference line for the roof (which will now be in line with the wall), and in the pet palette select the option for editing an individual roof plane. In the dialog box, set the offset parameter as desired to move the eave out away from the wall.

7. The wall outlines are adjusted to create an “L” shape. The bottom wall is extended to 28′-0″ or 9 m using the stretch option of the pet palette. The eye-dropper is used to pick up the setting of the wall tool, and a new wall is created to go up from that corner 12′-0″ or 4 m, then one more wall returns to close the addition. The extra piece of the original right-hand wall is trimmed away using the Command or CTRL-click method. (TIP: To do this successfully, make sure nothing is selected, and that your cursor is over the edge of the wall rather than a corner point; hold down Command or CTRL and click with the scissors, which should have turned black to show you that you were over an edge that it could trim.)

The roof tool is again selected, and the Multi-plane geometry Complex construction method is chosen. The magic wand is used to create multi-plane roof instantly around the entire group of walls. The result is viewed in 3D.

TROUBLESHOOTING NOTES: Sometimes the pet palette doesn’t “respect” or follow along with a choice that is made. I’ve found it useful to click a different button in the pet palette, then click back again to the one that I want; at that point ArchiCAD always follows along with the option I’ve selected.

Thank you for visiting the Best Practices Course website. The video lessons are available for members only. If you are an active member and would like to watch the ArchiCAD training video on this page, please login to the website. If you are not currently a member, please visit the following pages for more information and to sign up for the Best Practices Course, the QuickStart Course or for the Best Practices ArchiCAD Coaching Program. Eric Bobrow, Creator of the Best Practices Course

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ArchiCAD Training: Intro to Roof Construction for ArchiCAD 15

Let us know how you feel... (17 comments so far)

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  1. ToddFulmer
    3 years ago

    Eric, I have a student who will be using Archicad 15 for the first time in a competition. We have been looking at creating a roof and he asked how you would do a gable roof that attaches with a shed type roof over a porch. I am not sure exactly how to do that. Do you have any suggestions? I assume create the gable over the main body of the house and then use a single plane roof over the porch and connect them some how.

    • Eric Bobrow
      3 years ago

      Todd –

      The basic idea is correct. Create the main roof and the single plane roof then select both and use the Connect command. If this does not work, then you may need to select the main roof and edit the contour polygon to cut out space for the single plane roof. Be sure to edit the contour polygon, rather than the reference line polygon; this allows you to create a notch or do other simple changes to the coverage area of the geometry, without affecting the actual pitches or planes of the roof.


  2. Katharina
    4 years ago

    Dear Eric,

    I can only repeat the ones who spoke before me. I love to learn from you. I am enjoying every minute of it. ArchiCAD is fantastic!

    The only problems I have when some setting are not right, but I’m having a blast figuring it out!


    • Eric Bobrow
      4 years ago

      Katharina –
      I am so glad to know that you are enjoying the videos and making good progress in learning ArchiCAD!

  3. EstherOmenka
    5 years ago

    Hi Eric,

    These tutorials are fantastic, so easy to follow and just imagine what i can do right now within the shortest possible time as a beginner. Thank you very much.

    I have followed the tutorials this far without a challenge except that my shed and gable roofs on the first two boxes ended up at the bottom of the box of walls until i used the pet pallets to elevate them in the 3D view. Please can u explain how I can correct that on the floor plan.


    • Eric Bobrow
      5 years ago

      Esther –

      Thank you for your kind words about these tutorials. I am delighted to read about how fast you are learning ArchiCAD!

      The height of the roofs is set in the Info Box or in the Roof Settings dialog. If your shed and gable roofs were at the bottom of the box of walls, then you probably didn’t pay attention to setting the height before starting to draw them.

      Just like other tool settings in ArchiCAD, it’s a good practice to double-check this before you create the elements. Of course, it’s not usually a big problem, because you can always correct the settings after the elements are in place (as you did), either by moving them or by changing the settings in the Info Box or Roof Settings dialog.


      • EstherOmenka
        5 years ago

        Thanks Eric, this is well highlighted in the part 3 of this module.

  4. Arielle Schechter
    5 years ago

    Eric, your tutorial is a godsend–especially this one. I find the roof cropping in AC 15 to be somewhat counterintuitive and harder than 14 (because I’m not used to it, I’m sure). Without your clear and patient explanations, I would have been tearing my hair out over ArchiCAD as I did in the past. I have gotten so much out of each of your training modules. Without a doubt, your quickstart and training courses are the best investment in my career I’ve made in years. Thank you!!

  5. Graham Hobbs
    5 years ago

    Regarding Roof Slope in AC15. The rise and run settings for AC15 shown in this video appear to be available only in the US version of AC15.
    See my post and others recent at this Archi-talk topic:

    • Eric Bobrow
      5 years ago

      Graham –
      Thank you for sharing this interesting (and perhaps frustrating) observation. I will keep this in mind as I talk about how ArchiCAD works outside the U.S.

  6. Paul Demars
    5 years ago

    In your last example you made a complex hip roof. could you have chosen to automaticlly make a complex gable roof with v15?

    • Eric Bobrow
      5 years ago

      Paul –
      Yes, you can make a gable roof automatically with AC15, just as easily as a hip roof. Before this version, one could only make a hip roof; to make a gable, one had to create each of the two roof planes as a separate action, rather than in a single step.

  7. AlbertAeberhard
    6 years ago

    Hi Eric,
    Your lessons are fantastic. I alreay improved my drafting speed ten fold.
    I am having a challenge with the roof editing.
    In ARC14 we were able the select a singe roof pane and adjust it as we wished.
    In ARC15, the whole roof is selected and I cannot edit a single pane.
    What is the solution??

    • Eric
      6 years ago

      Albert –

      I’m very glad to read your general comment about the lessons and your drafting speed improvements.

      When the whole roof is selected in AC15, you may edit the polygon outline for the roof system by pressing down on the outline and using the pet palette. This allows you to adjust the outline for the single roof plan you mention, perhaps lengthening it or cutting out a part to go around another building element.

      You may edit the slope angle of a single plane by pressing down on the edge of the pivot line polygon (the inner polygon that defines the plate height of the roof), and selecting the appropriate pet palette option to set a custom plane angle.

      However, if you would like to make an individual roof plane have a different pivot line height, or break the connection to the other planes, then you will have to create a separate roof item.

      Alternatively, there is a command in the Design menu to split a complex roof into individual roof planes. This allows them to be edited in the “traditional” way. I have used this when working on a remodel project, so that I can split up roof planes into existing, demo and new polygons.


  8. MariyaLilith
    6 years ago

    Hi Eric,

    I like the new way of using SEO, trim to roof, in AC15. Thanks for explaining.


  9. JulianaPerrucci
    6 years ago

    great easy to understand explanation for roof construction both in 15 and earlier versions… made it all so much clearer.