Revit 2025 – Mullion Orientation on Conservatory Roof

by John Flanagan

Introduction

This blog looks at a problem with mullion orientation on Conservatory Roofs in Revit Architecture.

Sloped Glazing and Mullion Orientation

Figure 1 below shows a typical glazed roof construction for an external conservatory.

Initially the conservatory looks fine, but on closer inspection we can see that there is an issue with the mullions running along the apex of the roof. Refer to figure 2.

The mullions running along the apex of the glazed roof are splayed at an angle, but they should be perpendicular. To rectify this, we need to rotate the apex mullions (Fig 3).

• Find the angle between the mullion and the vertical plane. This can be done in a section view.
• Draw a vertical reference line up from the roof apex and measure the angle between the reference line and the mullion.

Now that we know the angle of displacement form vertical the mullion properties can be changed. To modify the mullion angle, follow the steps below:

• Select the splayed mullions as highlighted in blue in figure 4 below.
• In the Type Properties Dialogue duplicate and rename the selected mullions. Refer to fig 5.
• In the Type Properties under constraints change the angle to 20 degrees and click OK.

The mullions at the roof apex will now be perpendicular without any gap between them as illustrated in figure 6.

Note: It is necessary to duplicate and rename the mullions whose angle properties are to be changed otherwise the angle of all the conservatory roof mullions would change.