The essence of the BIM involves the fact that a design is treated as an integral part of the building life cycle. The work between the design parts and members is replaced by the adjusted process. This is achieved by changing the design technology substantially, switching from the development of a set of 2D drawings to the development of a 3D computer-aided model of a building, that consists of all the parts of the design, such as architectural, structural, mechanical, technological, construction process management and estimates. In the design stage, these goals are brought into effect by the technology of a Building continuum model, which focuses on the finally completed and fully equipped 3D building model comprising all the design parts. The base of this technology consists of the 3D graphical-information model covering the following: building a geometrical model; its physical properties (materials, etc.); functional peculiarities of its components. One of the fundamental innovations of this technology includes component modelling. The component modelling technology allows working in parallel with all design data at the level of data components covering the entire design cycle on the scale of a users group. Engineering components are graphical models of real objects. These models characterize geometry, properties, links, and attributes of the real objects. It is assumed that a building consists of elements and parts different by their functions, properties, and manufacture technology. Each part may consist of a simple structural component or a complex structure.
All elements or parts have a specific 3D shape with the properties of the elements of real structures (physical properties, class or standard). They are parametrically controlled and intellectual, i.e. each object “knows” about itself both quantitative information (length, area, volume, and etc.) and qualitative information (material, contents). All this provide unlimited possibilities not only to develop objects, to change and edit the shape of objects rapidly and effectively, but also to preserve and manage their attributive information, using the 3D building model. In the meanwhile 2D information, i.e. different drawings (plans, sections, facades, details, and nodes) and other design documentation (list of materials, specifications, reports, and estimates) are generated from the 3D model. Quantity and price of the specified components may be calculated by the measurement units required taking into account volume, area, length, or just by the parameter entered. Since these reports are linked to the model, new editions of the model update design data automatically. If necessary, external databases may be connected and used. Thus, accuracy, coordination, and synchronization of changes in the whole project documentation are ensured. BIM consists of discipline-specific solutions, working together. By applying information and model-based technology solutions to allow the automatic generation of drawings and reports, design analysis, cost estimating, schedule simulation, facilities management, and more – ultimately enabling the building team to focus on the information and their decisions, rather than the documentation tools and process. The result is a better way for building teams to work – with time saved, improved quality, and better buildings because of the informed decisions made along the way. Using BIM the entire lifecycle of the building is considered (design/build/operations). All information about the building and its lifecycle are included defining and simulating the building, its delivery, and operation using integrated tools. BIM integrates work, processes, and information for the following: multiple disciplines, multiple companies; multiple project phases.