BIM is Building Information Modeling
What is BIM, is it software? what are the best programs for BIM? Let’s talk about Building Information Modeling today
The acronym for BIM is Building Information Modeling: a model of a building with project information. Therefore, BIM is a methodology that if anything includes more software suitable for design and construction, used for its various stages of development.
Therefore, everything related to the building and construction sector is collected and combined digitally through BIM.
BIM is not software, but a complex and innovative methodology, essential for the main public construction, architectural, and infrastructural sector, because it is of strategic interest for governments but also for private individuals and all those large projects. BIM is also an integrated design method whose uniqueness lies in the ability to be able to collect, unify and combine all the data concerning the planning of a building design. The field of use of BIM affects both the ex Novo as regards the times and methods of execution and the future life of the building itself through the management and facility management.
When we talk about BIM, we are talking about a highly innovative sector that will invest the management capacity of the contracting authorities and design companies, and contractors who will execute the work.
In essence, BIM is not only used for planning the construction of a building, but it is also an essential method for the control, verification, and reduction of errors in the execution phase for a strict method of preventive control of the model.
History of BIM: how it was born and what were the first uses of this design method.
We can give an important development date of BIM, which coincides with 1987, the year in which the first real “experiment” of BIM took place, through the use of a virtual construction that was conceived with the help of ArchiCAD.
From that moment, BIM had an increasingly marked development, even there were not a few discussions and doubts about the term used for its name.
Today BIM is defined as an integrated process of sharing the information obtained and not only, therefore, as a method based on information: there is a sort of multi-disciplinarity of this methodology, and it is, therefore, true that its use is fundamental today. in the construction sector.
Over the years, then, it has always evolved into an indispensable methodology for large-scale works in which a dispersion of data can occur and through which it is possible not only to plan and manage but also to develop the virtual models produced with other software.
What is BIM for
A project can also be fully implemented with the aid of this methodology which, as specified, makes it possible to combine the “forces” of a large number of technical professional categories in the construction sector.
The key to the efficiency of BIM design is therefore to be a sort of multidisciplinary platform in which the operational competition of designers working within a project to build a model can take place with a certain ease and ease.
However, BIM has interesting uses and functionalities, whether it deals with the construction sector, as mentioned, or whether it refers to the facility management sector.
In detail, therefore:
• Within the facility management sector it can be very useful for the management, planning, and control of aspects and resources related to the maintenance aspect of a building
• Within the construction sector, BIM is very important because it allows a correct development and adequate management, without errors, of the multidisciplinary project in which all the parties involved in the project can therefore participate more easily. The multidisciplinarity we repeat, is therefore a characterizing factor of BIM: thanks to it it is possible to share and continuously control the process between the various subjects involved from the client to the executing company.
Attracted by the curiosity towards Autodesk Revit you will certainly have heard associated this software with two terms, BIM and parametric, within expressions such as: “Autodesk Revit is a parametric software” or “Autodesk Revit is a software-based on a technology called BIM”. Let us try to better understand the meaning of these statements by explaining the meaning of these terms.
Is it software? A three-dimensional model of the building? A technological process? A data collection?
The term BIM stands for Building Information Modeling and was coined by Professor Charles M. Eastman in the late 1970s.
The starting point is a three-dimensional model of the building; for this aspect, it could be confused with the 3D generated by any application.
The real peculiarity of BIM lies in the fact that the model is not only a representation in purely geometric terms of the building; it is a virtual reconstruction of the project, a pre-construction, through the use of components that are the virtual equivalents of those used in reality (walls, floors, pillars, stairs, roofs, etc.). Again, these “virtual prototypes” of the constructive elements are not simple geometries, but have their intelligence and are therefore able to relate to each other. In addition to that, they contain information that goes beyond mere representation (transmittance values of the material they are made of, fire resistance, manufacturer, etc.).
All this information inherent in our virtual building allows us to analyze it in depth (from a static, energy, lighting engineering point of view), thus being able to better ponder the design choices. The purpose of BIM is not just that of analysis; certainly of primary importance is also the aspect linked to visualization, which through the use of virtual materials, allows you to prefigure the appearance of a building in the context, as well as to evaluate different design solutions. The BIM model also contains a whole series of numerical data, for which there is no graphical representation (quantities, volumes, surfaces), but which can be extrapolated and reported in tabular form through specific schedules.
Thanks to all the information contained in it, its function does not end with the design and construction phases of the building, but rather continues during the entire life cycle of the building, during the management phase (Facility management) in to which economic resources far superior to those of construction are invested, contributing for example to more effective and rational planning of maintenance operations.
All these concepts have been taken up and perfectly integrated within Autodesk Revit.
The introduction of BIM represents a great revolution, and above all, a reversal of perspective for those who arrive at the use of Autodesk Revit from software, in this respect more traditional, such as Autocad. By traditional, we mean linked to a workflow that provides for the definition of a building through the creation of a series of descriptive drawings, plans, sections, elevations. When working with a BIM model, exactly the opposite happens, the building is completely reconstructed virtually, and the canonical drawings that describe it are derived from it. When you work with Autodesk Revit, you are creating an intelligent building model, which simulates and maintains the same relationships as the real counterpart. Let’s take an example to clarify the concept: when you draw an object, for example, a window, with software like Autocad, you draw a set of lines to which, by graphic convention, the “window status” is assigned. In a certain way, therefore, information is attributed to the project of which that window is a component. When we perform the same operation with Autodesk Revit, we create a virtual “alter ego” of a real window. This means that unlike what happens with other cads, in Autodesk Revit it will behave within the project as in reality: its placement can only take place inside a wall, and if the wall is subsequently deleted, the window too. it would disappear, instead of floating for the model, as would happen to the lines drawn in Autocad.
By expanding the concept to the entire project, we can affirm that at the end of the project we obtain the alter ego, or digital model, of a real building from which it is possible to extrapolate all the information necessary for the drafting of the explanatory documentation of the project.
This is another of the cornerstones of BIM: everything is grouped in a single database, unlike traditional Cad, where plans, elevations, sections can easily be separate files and above all disconnected from each other. In a BIM model, every modification to a construction element is updated in real-time, since the views are limited to “observing” the model and returning it to us graphically, or numerically in the case of schedules. All this does not only mean a greater speed in the creation of the documents but above all, total coordination as this is performed automatically by the software.
To simplify the concept, we can imagine positioning a camera that frames one side of the building being designed perpendicularly (in fact an elevation view). When a change is made, for example by changing the size and model of the windows, the image framed by the camera will be instantly updated; the name Revit means “Revise instantly”, that is, instant revision. If there are more than one camera positioned (plan views, section views, etc.), the change will instantly propagate to all these views. Not only that, if concerning the windows, within the documentation produced there is also an abacus, the update will also affect the latter because even the schedules, in Autodesk Revit, are considered views.
But the question does not end here: if the views in Autodesk Revit are “connected” to each other (since they all frame the same data model), then it is possible to make changes to the building model from any of them, by freely choosing the most suitable for the type of change to be made. For example, it is possible to modify a building not only from plan views but also from elevations or sections; or even from the abacuses! This way of proceeding, combined with what has been explained above, concerning the “real” behavior of the elements that make up the project, allows any errors or inconsistencies to be highlighted in a preventive way, significantly reducing the number of “surprises” in phase implementation of the project. As an example, as regards the associativity of the views, it is possible to assign the name to a newly created room directly from the plan view that “frames” it, or from the schedule view that counts it. Or, you can move or adjust the tax elevation for a window directly on the elevation or section. In practice, Autodesk Revit, thanks to its internal relational engine, takes care of all those revision and updating operations that other software imposes on the operator, leaving the user more time to devote to creative activity, the true aspiration of those who work in the field of architectural design.
Before understanding how this is possible, let’s examine the first statement: “Revit is parametric software”. In computer science, the parameter is a value to be assigned to a function so that it can perform its work. We can also affirm that parameterizing means representing an entity using parameters. Think of a wall, for pater to be represented it needs, among other houses, a value for the parameter “Width”, intended as thickness, without which its creation would be impossible. Parametric software such as Autodesk Revit is, therefore, a program that expects to receive from the user values for the parameters, or properties (for example Width, Height, Material) of the objects that the operator intends to represent through its use. In practice, it is a question of inserting information that, as we have seen, can vary at any moment (dynamic information) and which are used to define the characteristics of an element. This same information is what is used for the creation of the virtual model of the building, as a result of the elements that compose it, and therefore can be extrapolated from it for the drafting of the project documentation. The parameters constitute the point of contact, the common language between the designer and the software.
At this point we have analyzed the meaning of BIM, examined some of its advantages and what it means to deal with parametric software.
It is therefore time to analyze how the design workflow will unfold in such an environment. In reality, you shouldn’t expect anything complex; Autodesk Revit was conceived to simulate the real construction of a building and everything that composes it, through its specific tools, therefore in use it is sufficient to apply the logic that you would use on-site (in the discussion forums, one of the most frequent problems of use, is: “think about how the bricklayer would do it”). The first step to take is to define the spatial references within which the project will be developed, that is, the fixed wires of the structures through the use of grids and inter-floors for elevation development, using levels. The virtual construction elements will refer to these two-dimensional elements to establish their positions in space, for example, a pillar can be positioned at a certain intersection between grids, and its height will develop over a certain number of levels. Once the spatial references have been established, we move on to the positioning of the virtual building elements, walls, floors, roofs. Once the general architectural aspect has been defined, we proceed by inserting the openings, doors, windows, curtain walls, and then move on to the vertical connections with the stairs, and so on until the completion of the building.
Once the modeling of the building and its floor plan has been completed, it is time to start describing it to the interlocutors of the building process, such as the client, the administration, the company. We then move on to the documentation phase, in which new views are created, in addition to the basic ones used for the creation of the model, to achieve an optimal description of the artifact under the graphic aspect (and quantitative through the use of abacus).
Once the views through which to document the project have been defined, we move on to the integration of the graphic information present in the latter. Both with the addition of elements for the definition of construction details, and through the use of annotation tools, to provide numerical and textual information, using for this scope the dimensions, the keynotes for elements and materials, text notes, etc.
When the model is adequately documented and accompanied by descriptive, numerical, and textual information, necessary for its optimal understanding and consequently execution, the canonical technical tables are produced by putting together the previously developed views.
On the sidelines of this sequence of work, (which as you can see does not change in the steps, compared to any design job you have already faced) having worked with a model, which among the innumerable information that characterizes it also possesses the material ones, we find the ability to run rendered views. As we have hinted between the lines, using Autodesk Revit does not have as its primary objective the creation of a 3D model from which it is possible to obtain realistic renderings, if anything this possibility must be seen as a natural consequence of the design process.