BIM level 2

NB BIM Level 2 was superseded by the UK BIM Framework in 2018.

Building Information Modelling (BIM) is a very broad term that describes the process of creating and managing a digital model of a building or other facility such as a bridge, highway, tunnel and so on.

There are a number of 'levels of maturity' of BIM:

Level 0 describes unmanaged CAD (Computer Aided Design).
Level 1 describes managed CAD in 2D or 3D.
Level 2 involves developing building information in a collaborative 3D environment with data attached, but created in separate discipline models.
Level 3 has yet to be defined in detail, but it is thought that it will include a single, collaborative, online, project model including construction sequencing, cost and lifecycle management information.

In the UK, the Government Construction Strategy published in May 2011, stated that the '...Government will require fully collaborative 3D BIM (with all project and asset information, documentation and data being electronic) as a minimum by 2016'. This represents a minimum requirement for level 2 BIM on centrally-procured public projects from April 2016.

The processes necessary to achieve level 2 BIM are set out in:

These Publicly-Available Specifications are supported by a number of protocols, standards and tools:

CIC BIM Protocol. This establishes specific obligations, liabilities and limitations on the use of building information models and can be adopted by clients to mandate particular working practices. It can be incorporated into appointments or contracts by a model enabling amendment.
Uniclass2015. A classification system that can be used to organise information throughout all aspects of the design and construction process.
Industry Foundation Classes (IFC). The standard data format facilitating interoperability between different software systems.
COBie (Construction Operations Building Information Exchange). A spread sheet data format for the publication of a subset of building model information focused on delivering building information (rather than geometric modelling), such as; equipment lists, product data sheets, warranties, spare parts lists, preventive maintenance schedules and so on. COBie presents information in a more accessible format, so that it is easier to use and re-purpose. This is essential to support operations, maintenance and asset management once the built asset is in service.
BIM Toolkit. Developed by NBS, and offering a Digital Plan of Work to help define roles and responsibilities for preparing information and a verification tool to identify correctly classified objects and confirm that required data is present in the model.

Very broadly, the approach required by PAS 1192-2 ensures that appropriate information is created in a suitable format at the right time so that better decisions can be made throughout the design, construction and operation of built assets. The information is described in the Employer's Information Requirements (EIR).

To ensure projects are properly validated and controlled as they develop, data is extracted from the evolving building information model and submitted to the employer at key milestones. This submission of data is described as a 'data drop' or 'information exchange'.

Generally, data drops are aligned to project stages, and the information required reflects the level of development that the project should have reached by that stage. This might be considered analogous a stage report on a conventional project.

Data drops are likely to include:

The BIM Toolkit can be used by the employer to help define the level of definition required in the model at key data drops and then to verify that the required data is present.

NB: It is thought that in parallel to the roll-out of BIM, the government will require adoption of the Government Soft Landings protocol (GSL) for central government projects. Soft landings is a strategy adopted to ensure the transition from construction to occupation is 'bump-free' and that operational performance is optimised.