BIM level 0: This is entry level BIM where the processes and principles of BIM are used but without a 3D element.
BIM level 1: Level 1 BIM demonstrates a move from 2D to 3D and indicates the expected progression a stakeholder must undertake in order to reach level 2.
To be BIM level 1 compliant a user must employ CAD and also follow the guidelines from both BS1192 and PAS11192. By utilizing the associated roles and checking techniques users can still deliver savings and efficiencies without the other obvious benefits of 3D CAD, but also prepare a foundation to move into level 3 BIM.
At the top end of level 1 3D CAD is used and when employed in conjunction with the other processes, a user is ready for level 2 BIM.
BIM level 2: At level 2 the aim is to encourage deeper collaboration between stakeholders while ensuring information is highly accurate. Through the use of a sharing process such as a CDE (Common Data Environment), each level of the chain will be responsible for the creation and accuracy of each BIM. When brought together these form what is known as a federated model.