About OmniClass

The OmniClass Construction Classification System (known as OmniClass or OCCS) is a means of organizing and retrieving information specifically designed for the construction industry. OmniClass is useful for many applications in the area of Building Information Modeling (BIM), from organizing reports and object libraries to providing a way to roll up or drill down through data to get the information that meets your needs. OmniClass draws from other extant systems in use to form the basis of its Tables wherever possible — MasterFormat™ for work results, UniFormat™ for elements, and EPIC (Electronic Product Information Cooperation) for products

OmniClass is designed to provide a standardized basis for classifying information created and used by the North American architectural, engineering and construction (AEC) industry, throughout the full facility life cycle from conception to demolition or reuse, and encompassing all of the different types of construction that make up the built environment. OmniClass is intended to be the means for organizing, sorting, and retrieving information and deriving relational computer applications.

OmniClass consists of 15 hierarchical tables, each of which represents a different facet of construction information. Each table can be used independently to classify a particular type of information, or entries on it can be combined with entries on other tables to classify more complex subjects.

The 15 inter-related OmniClass tables are:

Construction Entities by Function - Table 11 (ZIP)
Construction Entities by Function are significant, definable units of the built environment comprised of elements and interrelated spaces and characterized by function.

Construction Entities by Form - Table 12 (ZIP)
Construction Entities by Form are significant, definable units of the built environment comprised of elements and interrelated spaces and characterized by form.

Spaces by Function - Table 13 (ZIP)
Spaces by Function are basic units of the built environment delineated by physical or abstract boundaries and characterized by function.

Spaces by Form - Table 14 (PDF)
Spaces by Form are basic units of the built environment delineated by physical or abstract boundaries and characterized by physical form.

Elements (includes Designed Elements) - Table 21 (ZIP)
  • An Element is a major component, assembly, or "construction entity part which, in itself or in combination with other parts, fulfills a predominating function of the construction entity" (ISO 12006-2). Predominating functions include, but are not limited to, supporting, enclosing, servicing, and equipping a facility. Functional descriptions can also include a process or an activity.
  • A Designed Element is an "Element for which the work result(s) have been defined." (ISO 12006-2).

Work Results - Table 22 (ZIP) (National Standard 2012-05-16)
Work Results - Table 22 (ZIP) (Pre Consensus Approved Draft 2013-08-25)
Work Results are construction results achieved in the production stage or phase or by subsequent alteration, maintenance, or demolition processes and identified by one or more of the following: the particular skill or trade involved; the construction resources used; the part of the construction entity which results; the temporary work or other preparatory or completion of work which is the result.

Products - Table 23 (ZIP)
Products are components or assemblies of components for permanent incorporation into construction entities.

Phases - Table 31 (ZIP)
Life cycle phases are often represented by two terms used somewhat interchangeably in our industry. For the purposes of clarity and standardization, OmniClass defines these terms:
  • Stage: A categorization of the principal segments of a project. Stages usually are: Conception, Project Delivery Selection, Design, Construction Documents, Procurement, Execution, Utilization, and Closure.
  • Phase: A portion of work that arises from sequencing work in accordance with a predetermined portion of a Stage.
For purposes of usage in OmniClass classifications, a Stage is a higher-level of categorization and a Phase is a subordinate level of titling within a Stage.

Services - Table 32 (ZIP)
Services are the activities, processes and procedures relating to the design, construction, maintenance, renovation, demolition, commissioning, decommissioning, and all other functions occurring in relation to the life cycle of a construction entity.

Disciplines - Table 33 (ZIP)
Disciplines are the practice areas and specialties of the actors (participants) that carry out the processes and procedures that occur during the life cycle of a construction entity.

Organizational Roles - Table 34 (ZIP)
Organizational Roles are the functional positions occupied by the participants, both individuals and groups, that carry out the processes and procedures which occur during the life cycle of a construction entity. Table 34 can be combined with Table 33 – Disciplines, to provide a full classification of each participant in the creation and support of a facility.

Tools - Table 35 (PDF)
Tools are the resources used to develop the design and construction of a project that do not become a permanent part of the facility, including computer systems, vehicles, scaffolding and all other items needed to execute the processes and procedures relating to the life cycle of a construction entity.

Information - Table 36 (ZIP)
Information is data referenced and utilized during the process of creating and sustaining the built environment.

Materials - Table 41 (ZIP)
Materials are substances used in construction or to manufacture products and other items used in construction. These substances may be raw materials or refined compounds, and are considered subjects of this table irrespective of form.

Properties - Table 49 (ZIP)
Properties are measurable or definable characteristics of construction entities.

Copyright © 2017 OCCS Development Committee Secretariat
For more information about OmniClass email omniclass@csinet.org
Use of Omniclass tables in applications is governed by the terms of the OmniClass License.