PHPP—the energy modeling software for the Passive House energy-efficiency standard—requires users to input wall areas calculated to the exterior of the thermal boundary. By default Revit does not calculate wall areas this way. Gregory Duncan Architect created a workaround to create a wall schedule that can export meaningful information to PHPP.
UPDATE: Please see this update for a new method involving curtain panels instead of walls.
The following screenshot shows an exterior wall corner plan detail where a rainscreen wall assembly joins a brick cavity wall assembly. The green dashed reference lines indicate the extent of the exterior thermal insulation. This is the outside of the wall as far as PHPP is concerned.
In order to schedule the exterior wall areas with respect to the thermal boundary, create a wall type called PHPP Thermal Envelope and constrain it to the outer edge of the insulation. A green diagonal crosshatch makes it is visible when displayed with the “real” walls. This wall is in a future phase called Energy Modeling so that it doesn’t interfere with the New Construction walls and so that the New Construction walls can be used as an underlay.
Finally, I created custom wall parameters for Orientation Degrees, U-Value, PHPP Area #, PHPP Wall Group Number, and Temperature Zone and a wall schedule that can be exported to Excel and linked to PHPP.
This method is far from an ideal BIM solution, but it has been useful for keeping track of wall areas, even on a small consulting project for an architect who provided only hand-drafted drawings in PDF.
If you have any questions or suggestions for improvement, please email firstname.lastname@example.org.