The National Building Information Model Standard Project Committee defines BIM as:

Building Information Modeling (BIM) is a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its life-cycle; defined as existing from earliest conception to demolition.

A basic premise of BIM is collaboration by different stakeholders at different phases of the life cycle of a facility to insert, extract, update or modify information in the BIM to support and reflect the roles of that stakeholder.

The US National BIM Standard will promote the business requirements that BIM and BIM interchanges are based on:

• a shared digital representation,
• that the information contained in the model be interoperable (i.e.: allow computer to computer exchanges), and
• the exchange be based on open standards,
• the requirements for exchange must be capable of defining in contract language.

As a practical matter, BIM represents many things depending on one's perspective:

• Applied to a project, BIM represents Information management—data contributed to and shared by all project participants. The right information to the right person at the right time.
• To project participants, BIM represents an interoperable process for project delivery—defining how individual teams work and how many teams work together to conceive, design, build & operate a facility.
• To the design team, BIM represents integrated design—leveraging technology solutions, encouraging creativity, providing more feedback, empowering a team.