U Values of Building Components

The U values of building components can be defined in the structure libraries, project parameters or, individually, in the opened projects. Indicative U values have been determined for the building components in the structure libraries included in the basic software delivery. If the thickness or materials of a component are edited in the building model, the U value will not be updated automatically; it has to be redefined, if necessary.

• Walls

  If you edit the number, thickness or materials of structural layers, the U value of the building component is not updated automatically. If necessary, recalculate the U value of the wall and update the new value to the wall properties.

  The U value of a wall is displayed in the wall properties if you select all the wall parameters to be displayed in the Wall dialog box.

  Editing Wall Properties
  Wall Parameters

  If you wish to edit the U values in the wall library, note that editing the system wall libraries is not possible. You can only edit customer-specific wall libraries.

  Editing a Wall Library

• Windows and exterior doors

  The U value of a window is displayed in the window properties:

  1. Click the Properties button in the Window dialog box.
  2. Select Extra Data.
  3. The U-value is displayed in the Initial U Value field.

  The U value of an exterior door is displayed in the door properties:

  1. Click the Properties button in the Door dialog box.
  2. Select the Page 2 tab.
  3. The U-value is displayed in the U Value field.

  Editing the Opening Properties

  If U values have not been defined in the window or door library you are using, you can set a default U value for windows and exterior doors by adding the following keywords to the PARAMETERS file of the project:

  UVALUE_EXTDOOR "1.0" ! The U value of an exterior door unless defined in the library
  UVALUE_WINDOW "1.2" ! The U value of a window unless defined in the library

  You can edit the U values defined in the window or door library by editing the library.

  Editing a Window or Door Library

  The U-value is displayed on the Parameters page of the database view.

• Horizontal structures

  The U value of a horizontal structure is displayed in the properties of the structure.

  1. Select the cross section in the Area Properties dialog box.
  2. Click the Properties button.
  3. The U-value is displayed in the U Value field.

  Editing the Properties of Horizontal Structures

  If you edit the number, thickness or materials of structural layers, the U value of the building component is not updated automatically. You can edit the U values defined in the floors and ceilings library by editing the library. The U value must be determined for the basic layer of a volume.

  Editing a Floor and Ceiling Library

• Corner running meters, opening perimeters, horizontal structure perimeters

  The corner running meters, opening perimeters and horizontal structure perimeters of space volumes are calculated for the energy report. You can set the default U value for these by adding the following keywords to the project's PARAMETERS file:

  UVALUE_CRNEXT "0.0" ! U value of the wall's exterior corner
  UVALUE_CRNINT "0.0" ! U value of the wall's interior corner
  UVALUE_PRMFLR "0.0" ! U value of the joint between the floor and the wall
  UVALUE_PRMFLRINT "0.0" ! U value of the joint between the ceiling and the wall
  UVALUE_PRMCLNG "0.0" ! U value of the joint between the roof and the wall
  UVALUE_PRMDOOR "0.0" ! U value of the door perimeter
  UVALUE_PRMWIN "0.0" ! U value of the window perimeter

Editing U Values
Generating a Space Volume
Data Collected from a Building Model
Data Calculated from a Space Volume
Energy Calculation