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IFC Terminology

Room program and program mean rooms, Items and related data stored in the dRofus database.


A model in dRofus and in this manual refers to the associated BIM/geometric representation of a building. It may include many IFC files/segments.

Segment/IFC file

In many sizable projects, it is common to design multiple models and save them in separate files concurrently. These files are referred to as "segments" of the project or model. For instance, a segment could encompass the inner walls and floors of a building, while another segment would include the outer walls and roof.

Viewer file

A viewer file is the term for a file that has been converted into a format for displaying in 3D.

Server model

A central server model that keeps IFC models and gives users access to design files "from the cloud"

Local connection

A local connection means that you have IFC files that are connected locally (on your PC).

Main function

An organizational unit for future users. For example, "Administration" (IFCZone)

Sub function/department

An organizational unit that is part of a main function (IFCZone)

Room name

Name of a room function, such as "Office"

Room designation

Further description of a room function that together with the room name gives a precise and intuitive description of the room's activity/function. For example, "one person"

Room Data

Room Data Sheet attributes written to PSet associated with IFCSpace (or IFCSpaceType if RFP is set on a room template) was called "RDS"

Room template

Room type which may contain RFP specifications, Item list and covering schema (IFCSpaceType)

Room template code

Project unique code for a room template. For example "SR.001" (

Room function number

Project unique ID for a room occurrence (room "identity"). In dRofus the code reflects the room's organizational affiliation, i.e., the main and sub-functions a room belong to. It is often used as a "key" for the exchange of data between dRofus and BIM (It defaults to for export, but this can be changed in the configuration)

Geographical room number/Architect Number /Room Number

Room number based on the location of the room in the building. It often reflects the building, floor, and possibly a wing and serial number. For example, you can call a room on the 2nd floor of building A in wing B "A.B.202", and the next room on the right side of the corridor A.B.204 etc. in the projected model which then can be read into dRofus.

User room number

"User" room number for the building's operational phase.


item in the project (fixed and movable furniture, electrical, plumbing, medical equipment, etc.). Object types in dRofus (IFCObjectType)

Item Overview

Overview of all Items in a database

ASE - Items

Building and Items affecting the installation. I.e., items requiring a connection to the technical system or which may have structural consequences due to the weight/dimension, which are to be hung on the wall or ceiling/under a cover, etc.

Item (occurrences)

Occurrences of items planned in rooms

To be modeled

Item properties in dRofus. This property is important in BIM projects for two reasons, firstly it is communicated via plug-in to the planners, and secondly, for validating planned versus modeled Items.


A collection of rooms. These can be rooms which have the same characteristics or which are grouped for other reasons. In dRofus this is also where you can set various classifications on rooms (IFCClassification). It is exported as IFCZone if the classification is not set.

Programmed area

The room's planned area (often validated against the designed area to see whether the project is staying within fixed limits)

Designed area

The room's designed area

Type and Occurrence

A BIM object has both an object type, and an object occurrence. Many occurrences can have the same object type. For example: 200 identical office chairs in a model should (in theory) have one object type and 200 object occurrences.

Object type

The object type indicates the data that is characteristic for a type. It is comparable to a commodity. It is equivalent to Item in dRofus.


Occurrences are in principle all building components that can also be counted. For dRofus the Items/Item in the room are occurrences (to be counted)

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