OmniClass™ is a classification system for the construction industry, characterized as "a strategy for classifying the built environment." OmniClass is useful for many applications where organizing information is helpful. Most notable is its use for construction specifications, and its growing significance within the National BIM Standard-United States™. OmniClass incorporates as the basis of its tables other classification systems that describe the built environment and associated processes. The intent behind much OmniClass development is to combine multiple existing classification systems for many subjects into a single unifying system based on ISO 12006-2, Organization of Information About Construction Works—Part 2: Framework for Classification of Information.


OmniClass encompasses many of the positive aspects of legacy systems (like MasterFormat®) that it incorporates, while expanding the subject matter addressed to accommodate the demands of building information models and integrated processes in the AEC industry. OmniClass has become an important requirement within the growing area of product search and comparison. It supports the demand for highly articulated product information in BIM format, and can normalize and categorize detailed attributes/properties and processes developed and supported by the National BIM Standard and Integrated Project Delivery. Complementing OmniClass is theInternational Framework for Dictionaries(IFD) Library. The IFD Library is an international effort and is currently operating in the Netherlands, North America and Norway as part of ISO 12006-3, Organization of Information About Construction Works—Part 3: Framework for Object-Oriented Information, and other standards.

OmniClass Tables of Interest to Facility Managers

OmniClass has fifteen tables that break down the construction environment into discrete types of information:

  • Table 11 - Construction Entities by Function
  • Table 12 - Construction Entities by Form
  • Table 13 - Spaces by Function
  • Table 14 - Spaces by Form
  • Table 21 - Elements
  • Table 22 - Work Results
  • Table 23 - Products
  • Table 31 - Phases
  • Table 32 - Services
  • Table 33 - Disciplines
  • Table 34 - Organizational Roles
  • Table 35 - Tools
  • Table 36 - Information
  • Table 41 - Materials
  • Table 49 - Properties

Perhaps the most widely used standard for classifying construction information is MasterFormat published by the Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC), which provides the basis for OmniClass "Table 22 - Work Results." MasterFormat is primarily used by designers and constructors to break down a facility into components for construction processes and cost estimations.

Less frequently used, but of increasing importance for facility management is "Table 21 - Elements," the content for which is based on the CSI/CSC version of UniFormat™, an existing standard used to classify building elements. The importance of this to facility management lies in its ability to identify systems within a facility.

Increasing interest in the management of spaces prompted improvements to "Table 13 - Spaces by Function." This table merges several existing taxonomies including ones used by the Building Owners and Managers Association, the International Facility Management Association, the Open Standards Consortium for Real Estate, and Federal agencies.

The current edition of "Table 23 - Products" covers almost 7000 products used in the construction and operation of buildings. This table is of vital interest to facility managers because these are the products that are required to be maintained, tracked, repaired, replaced, and operated during the complete building life cycle. Their specifications and maintenance instructions are used to establish maintenance schedules. Their spare parts lists are used to set up storeroom parts requirements and establish supply chains. Table 21 combined with Table 23 can provide a way of organizing and accessing useful data for failure modes and effects studies, and reliability-based maintenance programs.

Both COBie (Construction Operations Building information exchange) and SPie (Specifiers Properties information exchange) use OmniClass tables to organize information created by designers and product manufacturers so that it can be submitted to facility managers efficiently.

Conversion of the largely ad hoc self-generated equipment classification methods used by facility managers within existing databases to open standards using consensus developed OmniClass tables is a step which can support the development of facility management programs. See Computerized Maintenance Management Systems (CMMS) and Comprehensive Facility Operation & Maintenance Manual.

Additional Resources