The BIM methodology, through some essential preliminary steps, leads to the development of a virtual model of the building which contains all the elements: architectonic, structural and plant engineering ones.


Every element is in close connection with the others

To obtain or exclude specific conditions, the elements can be properly bound. A nice project comes from the analysis and definition of the field of activity, from the definition of the roles, and necessarily from the share of the working environment.

Drawing form other disciplines, first among all the Project Management, by which any project could be represented by a triangle whose sides are: time, cost, and field, a universally recognized method has been defined to set and manage a BIM project.


Definition of objectives

Is fundamental to know the aim of the activities. The preparation of a BIM project cannot disregard from the knowledge of the phases in which the BIM model will be used. Depending on the phases, should be predicted the necessary fields to hold the information, the interchange formats of the files, and the software solutions to use. A BIM project aimed at the designing phase only requires less information and coordination than a BIM project aimed at the designing and constructing phases of that same building. Different again is the case in which the committee has expressed the necessity to manage the building with BIM. It is easily understandable how, in this last case, the elements chosen by the designers should provide the information and specific techniques of the producer, relative to review and maintenance, if expected.

Preparation of the BIM work environment

In the technical jargon is called BEP, acronym of BIM Execution Plan, the preparation phase of the BIM project. Between them all, that is the most important one from which depends the quality of the whole project. It is necessary to really know the aim. Based on the expected activities it will be established a specific BEP. Through the BEP the objectives to achieve and the ways to do so are defined. In the BEP the roles and responsibility of the whole team are defined. Models and starting documents and documents to be produced, the procedures to follow and the in charge means.

Definition of the roles

the BIM methodology is primarily based on the work of three principal figures, to study design, and manage the BIM projects. To all the figures involved in the process experience and knowledge of the subject, specific previous activities in at least one of the sectors, deep knowledge of the software and competences of the Project Management are required. The key figure of the whole project is the BIM manager. Usually he/she assumes the role of head of the order as regards the BIM. He/she reports directly to the Project Manager. Knows the subject and the software in use, prepares the work environment, checks on the quality of the project (BIM), and ensures the exchange of information between all the parts involved.

Data sharing

The main characteristic of a BIM project is the constant sharing, of data and information, between all the figures involved, during the whole process. The system capable of guaranteeing this fundamental function is the CDE – Common Data Environment. Through a CDE properly configured, designers of any discipline, project manager, cost accountant, auditors, have access to the data. The CDE uses the Cloud technology to make the data always available to everyone without any limit of time nor dimension. The CDE configuration is normally in charge of the BIM Manager, who, according to what was defined with the work team in agreement with client and supplier, creates the work folders and allows all the members of the team to have access to the project data – everyone according to his/her role and function.

Working tools

The software used in working environment BIM have been developed and implemented to allow performing at best according to the specifications of the methodology. Willing to divide the tools in categories, in the first place for distribution we can find the development tools of the BIM model, the editor, which is able to produce the virtual model of the artifact/product based on 3D parametric smart objects. The market offers specific tools for the development of the architectonic models, of the structural models, of the plants, mechanic (HVAC), plumbing, and electric. Tools for the planning and management of the construction site, specific solutions for the management and maintenance of the buildings have been developed.

Beating heart of the whole system is the central database. Here all the information on the virtual model of the product are “guarded”: physical characteristic of the elements, relationship, limitations, and anything else has been linked by the operators to the elements themselves. On the other side, the interoperability between the solutions is the brain of the system. Even if it is not perfect yet, the system of exchange of the information between a phase and the following one, as from a discipline to another, is the true added value of the BIM methodology. All the information inserted by each operator at every level are always present in the system and available to everyone.

Thanks to BIM it has been overcome the almost complete loss of information that there was in the CAD world, where at each step only graphic signs would remain. The passage of data takes place in a precise and complete way for the application developed by the company itself, it takes place in an improvable way, between different solutions. The free format IFC (Industry Foundation Class) is the standard for the transfer of BIM models, the ODBC are the standard for the transfer of information linked to the BIM model. For each discipline many specific formats have been developed, they are not definitive yet, still they are at the height of their development.

Considering the BIM model as mathematical model of the product has enabled the development of a series of applications of analysis and simulations. Applications for the structural calculation have been developed: they read the data of the BIM model, verify the structure through the finite elements’ analysis, suggest and automatically perform any structural adjustment, if authorized.

Applications for the energetic analysis of the building are widely used. From the BIM model they read surfaces, volumes, physical characteristics of the architectonic elements, designated use of the rooms, orientation, window areas, and so on. They give back charts, data, diagrams but above all images in which they distinguish – through a more or less intense coloring – the virtuous spots and elements from the improvable ones, giving to the designer a valid verification and control tool.


Quantities Take off

The solutions for the calculation of projections and estimates have been the first to use the information of the BIM model. Surfaces, volumes and quantities are directly read by the model with great advantages in terms of time and accuracy. Also, the BIM provides the quantities of objects not there in the virtual model. Designing a waterproofing sheathing is no use, because it can be managed just as an information. The BIM system calculates the real surface and a possible increase owed to the long edge of the walls. The estimates can easily be divided up by areas, floor, type of material or processing, using as a filter the information of the model. The speed with which you have the results enables to evaluate different design assumptions at the same time and adapt them to any possible variation of the project, as well.

Management of the variable time

For sure one of the most important functions, it allows to link time to objects and phases of work. The first application, by diffusion, is the simulation of the construction site. The BIM model, thanks to the interoperability, is linked to the WBS (work breakdown structure) which contains all the activities and processing, making a simulation of the construction site over time possible. This way the areas of work and of storage of the materials can be studied and defined. It can evaluate the consistency and timing of the activities. The safety plan itself can be developed on the basis of the BIM model.

BIM solutions for FM

FM (facility management) and O&M (operation & maintenance), even if recently present on the market, have already aroused great interest from the operator of this sector. The potentialities that a system of management and maintenance of the buildings based on BIM offers are multiple. In the prior systems you could only count on alphanumeric data and in some cases on simple floor plans, a reference to reality was missing as well as the possibility to work on real objects instead of numbers and charts. Above all, having the 3D model with the precise position of the plans and machinery brings enormous advantages to the maintenance. Waiting to have the models of new buildings developed in BIM to use for the management and maintenance, the sector operators are commissioning to specialized companies survay and development of BIM models of their own real estate with a dual benefit: having an updated and precise model of the state of affairs and managing on a BIM model the buildings.