In situations where rooms on the same level are at different heights, like a lobby, atrium, or vaulted living room, there are two ways to model, depending on the analysis you'll be running:
Follow these steps to create multi-height spaces:
Select Room that you want to convert to a multi-height space.
Change the height properties of one wall (this will change the height of all wall properties associated with that room).
Any adjacent, single-story rooms that share a wall with the multi-height space must be treated individually, meaning they will have their own walls that enclose them. Dividing walls can only be shared on a single level.
Each room can only have 1 height.
If modeling over two levels, check the 3D view to observe where roofs have been automatically generated.
Designing multi-height spaces for loadmodeling.tool is different due to how OpenStudio handles geometry. Multi-height spaces must be divided into distinct levels to be exported correctly. The steps to create them are:
Model the occupied area on the first level with normal-height walls and assign a template that best matches the properties. If it's an atrium, choose the "Atrium" template.
If this room is double height, create the 2nd top half of the space on its level and assign it a "Void" template, negating any additional loads to the space.
Confirm that the walls of the bottom half of the room have a height equal to the elevation of the level on which the top half is modeled.
Confirm that the ceiling of the bottom half and the floor of the top half both have an R-value of close to 0.
Repeat steps 2-4 if the room is triple-height or taller.
Although there is a floor and ceiling dividing up the double-height space, the thermal loads will behave the same as long as the R-value of the dividers is near 0.
Group the Atrium and Void spaces into one zone within loadmodeling.tool to condition them appropriately.
Check the 3D view to observe where roofs have been automatically generated.