OpenBuildings™ Station Designer Help

Roof Builder

Used to create 3D solids that represent common roof shapes including sloped, mansard, gambrel, hip, shed, and profile roofs. The roof acts as an envelope that contains the 3D solids.

Note: Placement is completed using the controls found on the Placement ribbon tab and the Property Panel which is loaded with the active Building element catalog items and properties.
Accessed from:


  • Ribbon: Building Design > Architectural > Place Architectural Elements > Roof
Note: This tool provides the following features when creating roofs:
  • When creating a roof, you first draw a shape to represent the roof footprint. Usually this is done in a top or isometric view. The roof also uses the ACS, enabling you to place an entire roof envelope on an angle.
  • For sloped roofs, you identify which lines in the footprint define the roof pitch. and which outline edges create a slope.
  • Roof forms slope away until they intersect the plane of another roof, forming a ridge. Slope base lines which intersect other base lines, extend sideways to meet the roof formed by the neighboring line. This forms hips and valleys in the roof.
  • You frequently place roofs and then often times change the slope of a certain plane, or change the sides of the roof that have slope. This utility enables you to make changes to the slope of the roof. The ridges and valleys of the roof are updated during the process.
  • The roof form can be extruded down from the top, or up from the bottom, and this displays in the tool settings Preview as well.
  • All the forms inside a roof envelope have the same assembly. For example, all the joists in a sloped wood roof share the same construction and material. A sloped roof is constructed as one roof. All segments and sub-parts share the same function, material, and envelope.
  • When a design calls for a roof to be constructed of different materials such as wood and steel, the wood roof portion and the steel roof portion are modeled as two different roofs with two different envelops.

Placement tab

Note: The Placement tab opens on the ribbon when placing Building elements. The Placement tab contains settings specific to the Building element being placed that are used to define the position, orientation or dimensions of the Building element being placed. Also available on the Placement tab, are a collection of Building common tools selected specifically because of their relevance to the Building element being placed.
SettingDescription
Roof Type
  • Gable () - Places sloped, gable, butterfly, hip, and shed roofs.
  • Gambrel () - Places gambrel and mansard roofs.
  • Curve () - Places curve roofs. Curved roofs are composed of solids that have a profile to them; usually a curve, arc, or circular shape. Use this roof type to create a canopy over an entrance, or a roof created using complex multiple B-spline curves. The profile is extruded along a path that can be composed of one or more line segments (linear or curved).
Base Offset Effective when a floor is selected in the Floor Manager as a reference plane. Sets the Z axis distance between the elevation of the active floor ACS plane and the elevation of the component being placed. The value defines offsetting roof member from the active floor, there by allowing to build roof at an appropriate elevation relative to the active floor. Base Offset can be a negative value.
Place By: Sets the construction and placement method for the roof.
  • Shape - The roof is created by selecting a shape. The shape defines the outside perimeter of the roof footprint.
Place From: Sets the placement of the roof relative to the data points that place the roof.
  • Bottom – The roof is placed from the bottom, upward.
  • Top – The roof is placed from the top, downward.
Delete Construction When on, the shape that is used to create the roof footprint is deleted when the roof is placed.

Roof Properties



SettingDescription
Catalog Type Selector Used to select from available Catalog Types. Selections made here updates the Catalog Item Selector combo box.
Catalog Item Selector Used to select from available Catalog Items. The Catalog Item Selector combo box contains several options and settings designed to make it easier to find the exact catalog item you need to place/change.

A generic example of Catalog Item selector options for searching, grouping and navigating

The Catalog Item list also includes user defined assemblies, and RFA catalog items, if any.
  • Search - Used to search for catalog items by name. Results are dynamically updated in the catalog items list. The searched text is also highlighted in the results.
  • Group By: - Used to list catalog items in groups based on values assigned to specific catalog item properties. Groups can be collapsed and expanded by clicking the down/up arrows on the group name headers. For instance, selecting Group By: > Type for a wall catalog type creates groupings with Schematic, Partition, WallComponent, etc headings. Catalog items which have Type defined as Schematic, Partition, or WallComponent will be listed under those headings. You can also select Group By: > Do Not Group to create a flat list with no grouping. (Exemption Mechanical).
  • (Large Icons) - Displays a representative icon for each catalog item listing.
  • (List) - Displays catalog item listings without any icons.
  • (Float) - When selected, the Catalog Item Selector combo box is detached from the placement/modify dialog, and becomes a separate dialog. You may prefer to have the floated dialog docked and always open over clicking the Catalog Item Selector in the placement/modify dialog for each catalog item selection.
    Note: The main dialog remains open and refreshes the thumbnail and preview in response to the selected catalog item.
    Click the Dock icon to close the floated dialog.
  • Recently Used - Lists catalog items that were recently selected in a "Group". This is useful because when you need to repeatedly place or modify the same catalog items, you do not need to repeatedly browse or search the main catalog items list.
Note: When you make your catalog item selection, it becomes the active part the Family/Part Toolbar.
Catalog Tools A split button located to the right of the Catalog Item Selector contains tools to assist with managing catalog data prior to placement of selected catalog items.
  • ( Match Element Properties) - Sets the current active placement/modify dialog settings to match the parameters of an existing, selected catalog item instance in the model. This saves a good amount of time when placing catalog items that need to identically match those that already exist.
    Note: The existing catalog item instance must be of the same catalog type selected with the Catalog Item Selector for the parameters to be matched.
  • (Reset to Defaults) - Resets the selected catalog item property values to the default state as defined in the catalog library.
  • (Edit Catalog Item) - Used to edit the selected catalog item. Opens the Catalog Editor, where you can create and edit new catalog types and catalog items. Catalog Editor can also be used to edit existing data and to view catalog item instance properties and values by definition.
  • (Catalog Item Manager) - Used to manage catalog items library into organizational dataset. Opens the Catalog Item Manager, where you can copy or move catalog items into the dataset, and promoting current catalog items by moving then across workset levels.
  • (Save Catalog Item) - Updates the active catalog item in the DataGroup System catalog library with the values currently shown in the Properties list box permanently changing the defaults for the catalog item.
  • (Save Catalog Item As...) - Used to save a copy of the selected catalog item as another catalog item (the default name adds the prefix " Copy of " <current catalog items name>). Opens the Save As dialog where catalog item definitions can be named before saving them to the DataGroup System.
Note: The Save Catalog Item and Save Catalog Item As... tools perform administrative tasks on DataGroup System catalogs. Administrators and users may want to hide the tool icons to avoid incidental or unwanted changes to their firm's dataset by setting the user configuration variables BB_CATALOGITEM_ADMIN_IN_PLACECMDS and BB_CATALOGITEM_SAVEAS_IN_PLACECMDS to "0", respectively.
Preview Displays the selected catalog item in the preview window. This display changes and the preview updates as various options are chosen. The preview also changes dynamically with some of the prominent settings on the Placement tab, e.g Height, Rotation angle, etc. A right-click in the Preview opens a Show/Hide Viewing Tools option menu:
  • Zoom In - Zooms in about center of preview.
  • Zoom Out - Zooms out about center of preview.
  • Pan - Moves the preview following the pointer. Click again to stop panning.
  • Fit - Fits the object to the extents of the preview.
  • Rotation - Sets the orientation of the selected item in the preview to one of the standard orientation options:
    • Isometric
    • Right Isometric
    • Top
    • Bottom
    • Left
    • Right
    • Front
    • Rear
  • Display Mode - Sets the display of the selected item in the preview to one of the standard display modes.
    • Solid
    • Wire Frame
    • Visible Edge
    • Filled Visible Edge
For Place workflow, the Hide/Show Preview controls displaying preview of the element currently selected for placement.
Slope Options Enabled for Gable and Gambrel roof types.
Tip: Recently used setting menu options are made available for continued use.
  • Slope Control – Roof slope can be controlled by three methods:
    • Rise : Run – Expressed as an equation of colon separated, numeric values for rise (vertical distance) and run (horizontal distance).
    • Angle (y°) – Expressed as a numeric angle value in degrees, from 0 degrees (horizontal) to 90 degrees (vertical). Values can be integers or decimal numbers.
    • Percent (x%) – Expressed as a numeric percentage value for pitch; the percentage of vertical rise per foot of horizontal run.
  • Slope – Applies the appropriate numeric expression (Rise : Run; Angle; or Percent) for the selected Slope Control.
  • Upper Slope – Sets the upper slope value for gambrel and mansard roofs. Enabled for Gambrel roof type only.
  • Lower Slope – Sets the lower slope value for gambrel and mansard roofs. Enabled for Gambrel roof type only.
  • Curb Height – Sets the height of the bend point ridge line (called the curb) where the lower and upper slope surfaces meet. Enabled for Gambrel Roof Type only.
  • Apply Slope All Sides – When used in conjunction with a gambrel roof, the tool creates a hip roof, when on. Used to create a mansard roof.
Note: An Alert dialog displays "There were errors creating roof, the roof may be distorted. Do you want to continue?" when improper settings prevent one or more roof panels, or the entire roof, from being created correctly. For example, setting Thickness to 0:0, because the materials used to create any roof must have some sort of thickness. A partial roof may be created if you continue, which can visually enlighten you as to what went wrong, and what settings should be adjusted.
Roof Parameters
  • Thickness – Sets the thickness of the roof form.
Structural Usage Lists Structural usage properties. Structural function and material properties can be applied (if undefined) to active catalog items making them fully promoted Structural members.
  • Structural | Function - Sets the type of usage for the structural member. Choices are Structural and Non-Structural.
  • Structural | Material - Displays the material property for the structural member.
Materials Lists Part and Family definition assignments. Clicking in the Value column cell opens a Family and Part selection box. Here parts and families are available from the option menus.


Thermal Transmittance Lists the thermal properties to apply to the active catalog item.
Identification Lists identification properties for the active catalog item type.
Acoustical Parameters Lists acoustical performance properties. The acoustic rating and test reference details are set here.
Fire Resistance Lists fire rating properties based on agency fire safety tests and classifications.
Construction Phase Lists design and construction phase properties for walls such as New Construction, Future Construction, and Items to be Moved.
Space Bounding Lists properties that can be defined as On/Off making the selected catalog item eligible for consideration during energy analysis.
IFC Override Lists IFC properties not automatically mapped to DataGroup System properties that can be manipulated for export.
Classification Building Classification Systems are supported by the DataGroup System. MasterFormat, OmniClass, and UniFormat property values can be associated with any Building element. Click the Value cell to open the Classification System selection combo box. The combo box is populated with selected classification system property values. It can be resized by clicking on the combo box's bottom right corner. Search for properties by name. Search results are displayed in the classifications hierarchy. Double click a property to select it. This action also closes the selection menu. The selected property displays in the selected classification system property value (on the Properties list).


Note: Information in the Value column rows can be completed by selecting the applicable cell to activate an editor field, an option menu, or a pop up dialog. This data is written to the element properties. Properties displayed with grey text are read only. Some of these are set in the placement tool's Placement tab, and can be modified there. The dividing bar between the Property, and Value columns can be moved to change the width of either area, or resize the dialog. A vertical and horizontal scroll bars are available to scroll and adjust Properties panel viewing and the display of data.
Key-in: ATFGENERATE ROOF [ Catalog_Item ]

Use the Catalog_Item argument to directly key-in the desired catalog item saved in the active DataGroup System catalog to pre-populate the tool settings. For instance ATFGENERATE ROOF Roof - 08 where "Roof - 08" is the catalog item name.

Note: The Catalog_Item argument is case sensitive. Be sure to key it in exactly as it appears in the catalog.
Note: This tool is enabled only when the MDL application ROOFBLDR is loaded. Selecting the tool icon automatically loads the application. Because ROOFBLDR is not loaded by default when starting OpenBuildings Station Designer, the key-in listed for this tool will not respond if keyed in before using the tool icon.
To place a hip roof
To add and delete roof panels
To modify the elevation of a ridge line
Parent topic: Building Roofs