Surfaces such as the Internal ceiling tree object occupy the next highest position in the hierarchy below that of the Room tree object. An internal ceiling can only exist if it is situated in a multi story building on a floor that is below another floor. That is, the internal ceiling is in contact with an internal space.

There are multiple surface types such as walls, partitions, floors, windows and doors, surface components, each with a common set of data properties and a unique set of special properties.

The Internal ceiling object, when selected, provides an entry point to the surface data on the Properties For: Internal ceiling dialog. Here, you can view basic surface data such as the surface category and sub-type (Internal ceiling) as well as dimensional data. The Internal ceiling’s Construction details are displayed in several sub-panels. The Internal ceiling has special properties related to its construction. These special properties when manipulated, affect the thermal calculations and energy simulations that are performed on the project building.