Building Height: Overall height from the lowest point of above ground conditioned space to the highest point. Regardless of the projects varying height, and/or multiple project roofs, the building height will be the total height of the project's thermal envelope. For reference, the building height is used to calculation the infiltration the building experience.
Height is important to capture because of Stack Effect which results in higher infiltration rates for tall building compared to lower ones.
This article can help explain why a building's height was miscalculated when using the Revit plugin.
Determine Height of a Sloped Roof
If your project has a pitched roof, then the building height might include this height if the interior space is occupied' attic space. If your pitch roof encloses unoccupied space, then do not include it in your building height calculation. In this case, the highest point of conditioned space is the ceiling of the top floor, below the attic space.
Below Ground space and Building Height
If your project has below-grade space, do not include height. The height is used when determining wind driven infiltration rate, therefore below-grade height is not required.