To define the BIM or Building Modelling Information, The US National Building Information Model Standard Project Committee has the next description:
Building Information Modeling (BIM) is a Computational illustration of physical and functional features of a facility. A BIM is a shared information source for info about a facility creating a dependable basis for decisions throughout its life-cycle; defined as current from original conception to destruction.
Old-style structure design was mainly dependent on 2D technical sketches (plans, elevations, sections, etc.). Building Information Modeling expands this beyond 3D, augmenting the three primary spatial dimensions (width, height and depth) with time considered as the fourth dimension (4D) and price as the fifth dimension (5D). BIM therefore gives more information than just dimensions. It also covers spatial relations, light analysis, geographic information, and measures and properties of structure contents (such as constructors’ details).
BIM includes demonstrating a design as groupings of “objects” – unclear and vague, basic or product-specific, solid shapes or void-space focused (similar to the shape of a room), that convey their geometry, relationships and characteristics. BIM design tools permit drawing out of diverse views from a structure model for drawing creation and additional practices. These diverse views are spontaneously consistent, being based on a single description of individual object instance. BIM software likewise describes objects parametrically; that is, the objects are distinct as parameters and relationships to other objects, so that if a correlated object is amended, dependent ones will automatically also change. Each model element can carry attributes for choosing and arranging them automatically, giving cost estimations in addition to material tracing and ordering.
For the specialists involved in a project, BIM allows a virtual information model to be given from the design team (architects, landscape architects, surveyors, civil, structural and building services engineers, etc.) to the main contractor and subcontractors and then on to the vendor/operative; each professional adds discipline-specific information to the single shared model. This reduces data losses that traditionally happened when a new team takes ‘possession’ of the project, and delivers more wide range of information to owners of complex structures.